I've been doing this for a few years (first manually, now via FastMail's MaskedEmail feature) with good success. The only issues I've had are when one service gives the address allocated to them to another, related service. An example of this that recently occurred was when a service I wanted to use only offered GitHub SSO. That service was then handed my GitHub-only email address. I've had the same thing happen at Kickstarter. Overall a win, but still annoying.