BuddyBoss and PeepSo have their own themes, so it is safest and most convenient to use them. They are of course compatible with WooCommerce and are great for meeting all your needs, but they also work with other themes.
You may be able to create an unexpected and interesting display using an unexpected theme.
This site was built without using the BuddyBoss theme.
BuddyPress can be installed on any theme, but it may require CSS adjustments or may not work well with some themes, and I think the same is true for BuddyBoss and PeepSo.
You won't know until you try.
Personally, I think that it's fine to have a few themes in mind depending on the content of the site, and that changing the theme won't make a big difference, so I think it's fine to have a few themes that you're good at and can use effectively.
BuddyBoss is an evolved version of BuddyPress, so just like BuddyPress, you can use any theme, but the crucial feature is the forum.
https://7buddy.com/creative/
bbPress will turn your forum into something like this, but for other themes:
https://seven2.mixh.jp/zoomlesson/bbs/
This is what it looks like.
This difference is huge.
When building your BuddyBoss or PeepSo you also have the option of choosing different themes.
That's all I wanted to say.