I started out with 2D in the late 70s', had been designing machinery drafting "on the board" for over 10 years before that. Used it professionally until 2006, started learning Solid Modeling with Solid Edge. Over the years after that used Solid Edge, Autodesk Inventor, and Solidworks. Once you get comfortable with Solid Modeling, you would absolutely hate having to go back to 2D! EVERYTHING about 3D is better. The only thing worse is the initial learning curve. Designing assemblies is exponentially easier in 3D modeling, and used properly parts can be parametrically related to other parts, so if you change one, affected parts automatically change also. All good 3D mechanical modeling, with proper constraints between parts, will allow you do move parts manually on screen to see how the parts move together, and can also be automated to watch an assembly move through it's limits to check for positioning and interference. Here is a layout I did in Solid Works for the Stuart Twin Launch I have been working on. I did this to check the valve timing in forward and reverse.
I still have my favorite 2D software (Anvil 100-MD), and Solidworks. I tried to modify an old design in Anvil a couple years ago, and it was drudgery at best.
Of the Solid Modeling software I used over the years, I like them best in this order: Inventor first, then Solid Edge, then Solidworks. Unfortunately, I now have a license of Solid Works I use in my retirement, as it was the only one I could get a legal perpetual license of at a reasonable cost at the time. Would still prefer Inventor, but Autodesk has gone the route of subscription only, which basically kills any thoughts of a hobbiest using it. You can get a student license, but it dies after 3 years and cannot be used any longer.
I know exactly what you are saying. I have an old copy of Inventor. It is wonderful compared to AutoCAD Architectural which is what I have to use at the moment. ACAD's 3D software works but is tedious compared to Inventor or solidworks or most other 3D software. I disagree on one point, however, and that is the learning curve. With both Inventor and Solidworks, I simply followed the tutorial which came with them. It was so easy, it only took two days to go thru the tutorials and that was all I needed. 3D from the ground up is so much easier to use than any 2D that it bites.
What most of these companies who write software don't seem to understand, is the first rule of economics: Lower your price, you will sell more and make more $$. If a company is large and has 10+ employees, then I can understand charging a ONE TIME high price like 1500-2000$, but this obviously knocks out small businesses (which the software sellers should be trying to grow), hobbyists and students. I simply will NEVER knowingly buy anything on a subscription basis. In 2000, I bought a screen-writing program called "Sophocles". If you knows anything abouts screen writing, you will hear this or that program touted as the best software today! But I'm telling you, I have used them all, and, altho' Sophocles is outdated in certain ways, it is STILL as good or better than the touted "best". ONe was allowed to put Sophocles on up to 3 individual computers with a perpetual liscense. ONly thing was, you had to re-up the liscense with the software company every time you migrated to a new computer. That was OK, not much of a hassle, a couple minutes and you were set. Well . . . . one day, Sophocles simply disappeared! No more communication. NO-one ever found out what happened to the writer/owner of the software. We are still wondering. Rumours abounded--they sold out to the 'big kahuna' of script software to stop competition, the guy got in an accidnet and died, he went to the moon and never returned, etc., etc., etc. Finally, someone hackt the software and now anyone can get a hackt copy. There seems to be no flack about that, and I am not worried because I have a legal copy so I'm thimpfking the fellow is ded. Too bad, it was and still is one of the best screenwriting softwares available.
One should never forget also, that there are certain companies, that is, military industrial companies, that WANT to pay a higher price! You thimpfk that is incredible? It is not. They get paid by cost+15%! So they drive the cost up and harvest a guaranteed 15% above that. It is criminal and I know because I workt for a military industrial company. We made a part that cost about 100$ to make, could have made a large profit at 500$, but instead sold it for 9000$ each and the company we made it for, turned around without adding a bit of value to it, tackt on another 16,000$, so a product that could not imaginally be worth more than 5000$ (much less in reality, however) was sold for a w2hopping 25,000$. We wonder where our tax $$ go. And that is 25 years ago. For your information, the companies who make the nuclear power stations are on the same dole. The nuclear power stations could be made for 1/20th the price tag but the corporations use tricks like hiring more people but do LESS work, drag out the work, buy stuff for inflated prices and on and on and on! They know exactly what they are doing. Fleecing the public who puts up with it.