Everyone is a candidate, all the time.
The only question is what are the parameters that would be attractive to you in your next job.
If you are a software engineering-type in the U.S., and you're reasonably good at what you do, you should assume from here on out you will be regularly contacted by recruiters. Instead of saying 'no, not interested', say "yes, and here are the top 3 or 5 key items that would make me consider looking at a new role".
One of those items should definitely be salary (then title, work content, product, team, etc). For those of you happy in your role, there should be a premium to get you to move. Make sure it's well above market. Remember, you're good, and you're happy where you are. There is always risk in moving to a new role!
Put it this way, it's much easier to say 'no' with a big price tag, plus you might be surprised at what you find out regarding a new opportunity.