That’s a good question. The advantage is that next.js is setup to work with Tailwind whreas ionic framework is not. There have been several questions in these forums asking how to set up tailwind with ionic-react but nobody has answered. It is notably quiet from the Ionic team.
Tailwind with work with create react app, there are instructions on the tailwind site, but it involves install craco and I don’t have the understanding to get it to work with Ionic.
It would probably be easy enough to do if you eject but I don’t know if you can eject - there is nothing in the ionic docs and I haven’t tried it as yet - but then you’re left with all the updating yourself from that point on.
This all leads me to go with next.js stack from now on. It would be great to hear from the ionic team about this though.