Their is tons of competition depending on how you want to attack the problem. Tailscale's problem imho is that their product does not scale well as required by large enterprises. One could argue nor do traditional VPNs, but they are already in place and workking so that product config already works, no need for change. The market is massive, but you need to be at a high abstration layer in my opinion, so that you can replace far more than just the VPN.
