You touched a different but very important issue: in this industry you need to recycle yourself, you need to stay up to date with new technologies that overcome

You touched a different but very important issue: in this industry you need to recycle yourself, you need to stay up to date with new technologies that overcome the old ones. Being old doesn't necessarily means being obsolete, but you need to deliberately avoid obsolescence. Sometimes the new shiny things are actually good. Some technologies fade and you should avoid fading with them. Assembly programming has become a niche for people that write compilers. FORTRAN is giving space to R and Python. Very few people still write COBOL.