upgrading most codebases is trivial. (unless ur stuck running on legacy junk like websphere)
where it gets tricky is migrating MANY codebases, en masse. but the world's evolved since then. there are amazing tools to help.
tanzu application advisor (paid)
openrewrite (oss)
arconia (oss)
moderne (paid)
there's no reason your code should be on such ancient technology. and now, more than ever, it's a HUGE security liability to be stuck on such ancient technology. haven't you seen the wave of AI-driven CVEs in the last year across the entire industry? it's a CSO's worst nightmare x 1000