If you plan to eventually migrate to SAS Viya, M8 is the perfect stepping stone. You can start using CAS actions now, making the final transition seamless instead of a "big bang" rewrite.
If you are in finance (SOC2) or healthcare (HIPAA), the FIPS and OAuth updates in M8 are non-negotiable for passing audits. sas 9.4m8
However, the software doesn't stand still. Through a series of "maintenance releases" (M1, M2, M3...), SAS continuously adds features, security patches, and performance enhancements without changing the core version number. The latest and most advanced of these is (Maintenance Release 8). If you plan to eventually migrate to SAS
Here is the business rationale for SAS 9.4M8: SAS continuously adds features