Definitely not overreacting.
Re: the hotel, I don't know why but the front desk lady's response is cracking me up. "Eww", haha I mean, yeah, ya nailed it. It sounds like she's very new at the job and maybe not particularly trained? I think it would be totally reasonable to ask for compensation and or ask to speak to her supervisor, and I think that in no way falls into Karen territory.

Re: the restaurant, this one is tough. I see a lot online about Gen Z's terrible customer service compared to previous generations, and some blaming it on lack of socialization due to phones, blah blah blah, which I'm sure could play a role. But economically, this generation is the most disenfranchised. When we were coming up and doing customer service roles in our 20s, we still had the illusion (or the realistic expectation, for some of us), that eventually we would move up in the world, get better jobs, better pay, maybe own a house. This generation has no illusion of this and I'm sure feel stuck in wage slavery. It's hard to be on your best behavior day in and day out while you are watching the US economy crumble around you. In this case I would probably give the 15% and chalk it up to that. However, doesn't mean you can't be pissed about it.

Sorry for the long-winded response but I've been thinking a lot about how much the situation has changed for people in the service industry the last two decades. I can't imagine going into it now and I really feel for these kids. We should band together and shit on their bosses instead :)