Personally, I like to upgrade my projects whenever a new MTS or LTS is released, which is the case now.
The most obvious benefits are to be able to make use of the newest changes and features. For Mx 9.24, you can read them here.
The main reason as Ayco stated, using the latest features. On the other hand, fixing bugs might be extremely important. You can read on release notes for known bugs details: https://marketplace.mendix.com/link/studiopro/
LTS (long tems support) releases are more safe than mts or others. Because Mendix says that this version is a milistone and we can provide long term support this version until new lts one is released by us. We can rely on this versions.
I hope that is clear for you
the Reason to use Latest LTS version for development is to use the new features and fixation from the mendix in previous version.. I personally upgrade to use new widgets and explore myself to Marketplace world.