There have been improvements in Layout, and some in SU.
None are life changing, but see the release notes, and decide if any are important to you.
Google for “Sketchup release notes” to find what was new in versions 2018, 2019 and 2020.
You can no longer purchase a permanent licence for any version of SU, only an annual subscription (but an existing permanent licence should continue to work indefinitely) until a new OS or hardware incompatibility makes it stop working.