Airdrops are still profitable but have switched to a newer form that people often call testnet or retroactive...but spam airdrops are just trash. Airdrop is just a form of earning free altcoins and I think it has nothing to do with investing in altcoins because not all altcoins launch airdrops for users.
Posi, you know, sometimes I used to think I started on the wrong path to cryptocurrency after some bad experiences, but yeah, I just have to realize that there is no smoke without a fire, despite those past experiences. Although some airdrops paid off well, like, luckily, $100, $50, $80, or more, I don't think there are any airdrops that can pay up to those amounts now, although I have given up on it for a long time now, so I am not certain, but like you said, it has switched to Testnest, which I don't know how Testnest works, but I remember doing something like Launchpad where I connected my wallet to claim some free airdrop coins too, which was even worthless and my wallet was hacked.
Focusing only on bitcoin is not a bad idea because you will avoid the risks that the altcoin market brings. But you will also miss out on the opportunity to gain big profits from investing in altcoins.
From your account registration date, I believe you are a well-experienced crypto user, and you have seen so many altcoins bloom and dump, and some people also became millionaires because of it, but sincerely, that's all luck, and I have also bought so many altcoins but was not lucky. I really don't like to hold altcoins like Bitcoin because I know it can pump and dump, and after it has dumped, it might likely pump again. I bought a lot of meme coins, but they are still in my wallet, looking worthless. So, I think Bitcoin will not just be a thing of luck while investing in it; I believe it's an investment that will surely bring profit in the future, not like altcoins that you are not just sure of. I don't totally hate altcoins, brother, but even while I have been investing in altcoins, I already miss a lot of opportunities, like Shiba Inu, Pepe,Gom, etc. What more could I miss before I decide to start buying altcoins again?