Once you get to a certain level in speakers, it will take a LOT to "max them out" with the backing gear. Say you’ve found a high-end speaker with a voicing and aesthetic you love, you can live with its trade-offs, and it’s the right size for your chosen domicile. "Upgrading" from this could be a nightmare, because it can change EVERYTHING you’ve been building synergy towards, and there’s no guarantee the new speaker will be a good fit for your room. It’s not like dropping in a preamp - you’ll have to position, reposition, and re-reposition the boxes and seating. It could well set your system into a tailspin that takes lots of time (and money) before settling again. And don’t forget about burn-in. If you have to swap out or return speakers, shipping is an order magnitude more hassle than with electronics components.
That’s why some of us choose to keep the speakers we’re happy with and pump more money into the upstream.
That said, your post specifically cited $2K - 5K speakers, and honestly - no, I could probably not stay put & happy with that.