[skinnyarms]

Just search for "overdrive pedal" on Sweetwater and you'll see a lot of pedals that have been around for decades. Read up on the newer ones and you'll see they generally just add novelty options and variations to classic designs. You can easily find comparisons of schematics by googling, though it's not as simple as "Tubescreamer 85 vs Tuberscreamer 2023" because of various small evolutions and models. Try "tubescreamer circuit comparison" to get a good start.

Delays are another story, search Sweetwater and you'll see it's dominated by digital options that bundle things modulation, stereo effects, and loopers. You won't see the same analog options as the 80's, or many analog options at all comparatively.

[klodolph]

A lot of the analog options are still around because bucket brigade devices are still manufactured. So you can get a Boss CH-1, a Memory Man, or something like that, new from the manufacturer.