I think OPs problem is going into management. Base pay is typically higher than an IC but a high flying IC can clear more easily. As you mentioned specializing is the key. Data engineering is the new hotness. Failing that, I can echo your sentiment on the contract market. I can (and have for a short time) doubled my employee salary after taxes going self-employed. If you can keep a list of clients and not work for a contract firm (which is hard but doable) you have a lot of avenues for better benefits via SEP-IRA, entrepreneur healthcare programs, etc that you will never get as a W-2.
