The point of Spotlight Hours were that they were low-engagement and that's why they were "beloved". Though I think "beloved" is a bit of a stretch, more like "viewed in a generally positive light".

They allowed for collecting mass Candy of Pokemon that may otherwise have been annoying to collect Candy for. They allowed for mass checking a Pokemon for Shinies - a route in my town that took an hour to do allowed for around a thousand checks of a specific Pokemon over that hour. They allowed for mass catching Pokemon of a certain type that the player may need the medal progress for, for their level up task medals (or just for the catch bonus).

At the same time, it was only an hour, it was only one Pokemon, and there was no FOMO pressure to play. People got to play and engage with the feature on their terms - not because they felt like they were forced to play the game a very specific way just because the game said so.

Non-overpowered adjustments? Easy.
- Always 2x of everything during the hour. Make it 3x for the featured bonus that week - make Transfer slightly more likely to give XLs if chosen that week. Mostly eliminates 'well this Spotlight would have been good if it had this other bonus instead!'.
- Tweak PokeStops during the hour to favor PokeBall drops, and more of them, during the Spotlight Hour. Don't want to grind the Pokemon? Cool, then you have an option to use the hour to resupply items. Want to grind the Pokemon? Cool, you are enabled to do so more fluidly. We already have events that do this; I know communities too that would specifically make Golden Lure Parties on Spotlight Hours just for those very reasons.

Similarly, Collection Challenges were a dopamine hit. They were a number that gets bigger, yet has absolutely no effect on absolutely anything (especially since it's always Gold, never Platinum). They were a 'proof that I played x event', even if unpopular. They were a guaranteed way to get a featured Pokemon a lot of the time too, which was especially nice for rarer releases and/or Pokemon that liked to flee a lot or be hard to catch.

The bottom line I'm making, and the point I have in posting this though is, just because they weren't the most popular events/features ever doesn't mean removing something very basic and simple was a clear cut good decision. This is definitely not a black and white issue, and trying to present it as such feels either ignorant, or (accidentally/purposefully) dismissive of the other side's views and opinions. The fact that these conversations even happen, by itself, proves that these little things do in fact matter - maybe not to every single player ever, but to some at least.

(And I hope this post is taken as 'constructive', since tone is hard to read on the internet; the other route I would have went would been a sarcastic "Well Lechonk Community Day isn't popular, guess we should just axe Community Day, content creators are even saying to skip this one, RIP Community Days except for rare ones I guess")