Something I've been thinking about for a while is the impact speedrunning can have on a game's overall popularity and whether or not game developers have intentionally added, or refused to fix bugs in particular titles with the hopes that speedrunners would exploit them, more people would run the game, and the game would become more popular and potentially bring in a lot more revenue.

Are there any notable examples of this happening in the past? If so, how successful have these efforts been and how would something like this impact the speedrunning scene in the future?

It's not quite the same, but the Streets Of Rage 4 developers are very open to feedback and have a bug report channel in their Discord.

A big balance patch was released that resulted in us having to split the boards as it changed so much. Some of it really helped speedruns (items that 'bounced' could now be picked up) some it hindered the runs (there are more random elements in for instance Stage 1 that can kill a run automatically).

I don't envy being a dev in this day and age where balance patches are expected and you are trying to balance the will of the casual market, and that of speedrunners who breeze through the game.

I think that the bugsnax devs said they wouldn't patch many of the skips in the game because they have to be done on purpose (they wouldn't happen on accident to a casual player), but fixed other glitches that could happen to a regular player by accident.

I think that game devs should just try to make a fun game casually, and not focus on the speedrunning aspect, outside of maybe adding a timer that the player can turn on. Adding complex features can overwhelm a casual gamer, or take away from a game's simplicity.

If a glitch doesn't hurt a casual player (who are 99.9999999999999% of players) then speedrun-friendly devs (who aren't common) sometimes leave it. That's about as far as it goes.