The issue all forums are built using a data structure, and exporting/importing this to a new platform would be a lot of work, or just not possible depending on the migration path.

Xenforo, invision, phpBB and maybe others can be migrated too, but I assume all would come with there own problems/challenges.

All forums have so many features and settings. I personally don't think the site is using them to the full advantages, for example the calendar section to put all the events into, if you don't know about things then it is hard to use/see them.

Also ads, these should be turned off for paying members, but show for none visitors/registered users.