> When I was cycling, there wasn't any compatibility between Shimano and Campagnolo (SRAM wasn't a player in road yet). Heck, Dura-Ace (Shimano's top of the line road component group) previously wasn't compatible with other, lesser Shimano groups.

This isn't remotely true at all. For probably two decades people have been swapping Shimano components around, even stuff like putting dura-ace jockey wheels on lower derailleurs because the DA jockey wheels had better bearings and lasted longer.

Manufactures shipped bikes all the time with higher group shifters than a derailleur or brakes (manufacturers love to cheap out on brakes and front derailleurs in particular.)

BTW, Hammerhead is really important in the market because along with Wahoo they were the first serious challenge to Garmin's effective monopoly on bike computers. Frankly, they used to suck - little to no change between models. Wahoo and Hammerhead forced them to actually innovate. Amusingly enough, the first "new and competition-improved" Garmin head units were terrible - the Edge 500/1000 were buggy and tended to crash a lot. It took at least another product cycle or two for Garmin to get their act together.

A similar thing is happening in the GPS sport watch market. Some new competitors have shown up, and all of the sudden Garmin's lower-end sport watch lines are seeing massive expansion of their features which would normally only be found on much more expensive models.

Before 1997, Dura Ace wasn't compatible with other Shimano groups.

https://sheldonbrown.com/dura-ace.html

I may just be showing my age though.

Yep, I remember those days.

Somewhere between 2000 to 2010 was a golden age when bicycle components were much more cross compatible than before or after. SRAM was almost all Shimano compatible (cog spacing, freehub splines, etc, IIRC the only difference was cable pull for shifting) and for 10 to 11 speed you could drop a Campagnolo wheel into Shimano/SRAM system or vice versa without any noticeable mismatch. And during that time there was basically one common bottom bracket shell standard.

There are competing bottom bracket standards now? What a race to the bottom. Feeling even better about my 20 year old bicycle now.

  There are competing bottom bracket standards now?

Oh my sweet summer child.

Winter has finally come and the bottom bracket standards are everywhere.

I think this is all Cannondale's fault and I do resent them for it.

Yep. A few…

Threaded external (Sram GXP)

BB30 (plus a few offset/asylum variants)

PF30 (Bb30 but bearing is in a plastic carrier instead of pressed directly into frame)

SRAM DUB

And most have 2-3 widths (road, mountain, e-bike/DH bike/fat bike)

DUB is a crank spindle standard, and fits in lots of different bottom bracket shells. GXP is also a spindle standard that fits in different shells, most typically English threaded.

But to your main point, that there's a handful of modern standards, yep. There seems to be a good reason for each to exist, at least.

Which makes it worse. Not only does a consumer need to figure out the specs for the BB shell on the frame, but also the specs for the crank spindle.

On the plus side, at least Shimano has, so far, mostly stuck with a single spindle. Where SRAM has produced GXP, BB30, and Dub at overlapping points in time and within the same group of components.

And whoever invented BB30 (Cannondale?) needs a kick in the shin. I’ve never been happy with a BB30 frame - they’re all destined to squeak and creak and pop at some point. Maybe a good standard for a race bike that gets torn down frequently, but just terrible for a consumer bike.

I think it's a part of the problem that consumers keep buying race bikes even if they're really not good for all around riding without support from a team mechanic. It wouldn't be difficult to make a reliable and affordable road bike with 95% of the performance of a race bike (disclaimer: I just made up the number) but selling it would be a challenge.

T47 (threaded) also joined the club more recently as a more reliable PF30 successor.

While Campagnolo is not compatible with Shimano/SRAM, when SRAM started up they built their own drivetrains as compatible with Shimano up to and including some of the 11 speed road components.