Buying BTC anonymously (avoiding centralised exchanges)

So far in my research I've come across 2 ways to buy BTC anonymously:
1) P2P platforms like Bisq
2) Cross-chain bridge apps like RocketX

Honestly second option (cross-chain bridge apps) looks much more attractive, better UI, faster and cheaper. Does anyone have experience with buying BTC on cross-chain bridge apps, and if yes, which ones are the best, safest?

PS. I tried to initiate this topic earlier, but my post was removed by moderator because "it primarily pertains to altcoin discussion". Honestly, I find this ridiculous. There are number of reasons why I would be interested in exchanging alts for BTC (for example receiving alts from a friend, or simply learning curve towards understanding that BTC is the best), and I don't see how I am being "disrespectful" towards BTC while trying to find a way to exchange alts for BTC in a anonymous way by avoiding centralised exchanges. I hope this post doesn't get removed again. Anonymity was my primary reason behind this research.

PS 2. Before my post was removed, one person commented "you are buying Bitcoin with a shitcoin, not fiat". What exactly is the difference? I mean, who cares for what do you buy BTC. Feels like there's ton of judgment here unless your portfolio is 100% BTC.