I have a model and my own router; I don't use (or even have) one provided by my ISP. I'm not entirely sure how Tailscale works TBH, so yes I'm betting on them being secure.

Tailscale comes with a few other benefits that don't come on other VPN's. I have my home server setup as an 'exit node' which allows me to route my traffic through it when I'm travelling. Super handy sometimes like when I'm travelling and my bank decides not to let me log in.