Beg to differ, think you are wrong there. Sure, stock suspensions are better now than in the past but the "better" is usually in the ability to tune them. Suspensions have worked basically the same since Simons and Fox developed the cartridge fork in the '80's. Fox Air shocks from the '80's perform just as well as today's - even twin shocks.
I was out this weekend on my (new to me) KTM. I could barely ride it around our track. Even though the oil level and spring rates were correct for me, the initial part of the stroke was too harsh. A few minutes at the truck and I had it all dialed in. All my buddies, wanting to try the 2-stroke thought the suspension was the best they had ridden.
That is very different from when I went out there with my '80 Can-Am. With that, I had to take it back to the shop to disassemble, change the oil and change the nitrogen pressure to get it close. All done, the Can-Am works just as well as the almost 30 year newer KTM.
I then rode the 250F of one of those buddies and gave up after one lap. Not that it was a 4$, but that all those knobs and adjustments must have confused him. I'd take the Can-Am of that anyday!