LP's... Do they sound better now than 30 yrs ago?

Having bought a couple of thousand lp's over the last 5 years, vintage, new, a few audiophile releases too. For a general new vinyl re-release, non-audiophile 1 in 3 has a problem, usually warped, pre-scratched at the factory, surface inclusions etc, like a previous poster mentioned, some of the US plants are problematic, no QC.
(Best to buy these through Amazon, for ease of return/replacement).
 
I even try to buy the occasional expensive Audiophile release through Amazon if I can, for the same reason, the Doors 45rpm Analogue Productions series spring to mind, as i live far from the US, (returning a damaged Lp to Acoustic Sounds was not cheap).

For vintage vinyl, Discogs is a better bet than ebay  for general condition, but for me Germany is the country to buy from, cheap overseas postage and usually premium condition. On the other hand you get buyer protection on ebay which is good.

As for gear, someone already mentioned the bullet proof Rega Planar 2, I'd add the RP3 as well, these are plentiful on the 2nd hand market, and while not everybody's favorite, they are easy to keep tuned up unlike some finicky sprung turntables. They give a great sound, just make sure your support is not prone to vibrate, a reasonable cart like the Denon 110 will sound great and you can upgrade the tonearm wires (RB250/300), replace the the mat, and sub-platter  as you want later. (These are manual so if you need a tonearm lifter get a Thorens Q-Up to stick on).

Here's another 2 cents worth: I have occasionally picked up a rare record in amazing condition at a thrift shop for a buck, whats cool is some of the 60's vinyl is really resilient, and old beat up mono lp's CAN sound amazing with a dedicated mono cartridge (think Audio-Technica AT-3or 33 and others) which seems to eliminate most of the surface noise that a stereo cart will pick-up, HOWEVER if you only have one turntable/tonearm you will want to change the headshell out for ease (maybe an old Technics1200?) for this, another reasonable bullet proof turntable, (as long as it hasn't been DJed to death)

Hard to put a finger on when the mass market players started sounding good, straight off the shelf, could have been around the late 70's with the Quartz locked Japanese players? Some of the old idler drives sound amazing when replinthed into a solid base. (Anyone out there replinthed an old Elac 50H or 770H, you'll know they can sound pretty good, but not so in orig hollow box).
I remember when buying my first low end audiophile tt the advice I was given "want twice the quality, pay 10 x the price!"

Here's a take on modern remasters: https://www.reddit.com/r/audiophile/comments/47sbx6/opinions_on_bowie_vinyl_remasters/

I'm not so sure Rainbow has much to crow about, cast your mind back to the recent Beatles Stereo Lp re-issue program. The complaints about the problems from the Rainbow pressings vs the European ones pressed at Optimal tarred Rainbow as a 2nd rate pressing facility. (I'm not sure if they have upgraded their QC recently, but quality was not often used in the same sentence).