I mean, I think the problem with SPA-like client-side approaches are that there aren't any that have felt _good_ with Rails, let alone great.

Absolutely true that not every app needs to be a SPA from day one, but I do with there were a few more common solutions for "hybrid" apps, which use some pages as a SPA. That said, it's not that bad once you've got it setup. I like that Rails offers a solution like import maps, but I do also wish there were better core functionality for using some kind of package manager.

Like the redis analogy: Whether or not you need Redis, there are good defaults and very good 'third party' solutions for background jobs (or caching). You don't even need Redis is many cases, but it's easy to grow into.