I’m 58. I found myself in a similar situation. In 2010 I should have migrated a large web forms app to newer tech but my main client wanted to get a new partner up and running fast. So for six more years continued doing web forms, sql server,etc.
4 years ago we migrated to Azure (learned that), then AWS. Now we’ve got API Gateway’s. Learned lambda (node), built node/express API’s and are redesigning everything to React, node and PostgreSQL.
A lot of learning in 4 years but I’m glad I don’t feel outdated anymore.
At any point, your current skills have a shelf life.