My anecdotal observations suggest it's pretty different. One thing is you can (and do, if you're a kid) carry it everywhere with you and stare at it all the time. I think the phone UI where each app takes over the whole screen also increases the impact of the worst sorts of apps (like TikTok).
Interesting observation about everything effectively running in full-screen on a smartphone, taking it out of the larger context of whatever else you were doing before that.
Personally I'd think its different, smartphone apps usually have tons of dark patterns and are designed to always be with you versus a desktop or even a laptop.
It probably makes a difference that the internet of ~15 years ago was healthier to use than the half-dozen websites that encompass the entire internet for most people today. Attention-optimizing algorithms and infinite scrolling are some of the worst inventions that have come to the internet since the pop-up ad.
