Being a real estate agent is a job.
Besides the ongoing licensing requirements in terms of both time and money, it's difficult, IMO, to do as a minor side-gig, because you won't be in the deal flow. Doing it regularly gets you referrals from past clients, it means you're probably advertising, etc.
Doing it rarely means you don't have those incoming streams of deals, and it's much harder to do, because you're competing with full time agents who do have all those advantages. How do you expect a random home buyer (or seller) to find you to buy/sell something if you aren't advertising or they aren't getting a word of mouth referral?
YMMV, of course, but this is how I see it. It's a good job if you're a sales-type person. It's a poor side-gig, except for maybe rare one-offs from friends or family who know you have a license and are looking to save money.