I doubt it's legit, especially when the website design isn't very well designed and there's no mention which pool used to perform acceleration. In addition, that user seems to perform SEO spam which is common occurrence on this forum.
It’s definitely a scam, there have been numerous numbers of sites I was like that with different domain, which definitely makes it fake. An old thread of same thing is
here and if it has been working from day one we will have had it’s suggestions all round the forum like that of Viabtc. The sites also didn’t provide details of the transaction will get confirmed or the pools they work with as you have said. I will advise OP to just stay away from that site, they probably what they can do is to just rebroadcast transactions and claim it is accelerated.
This will gonna be a long wait considering how low the fee you use while Bitcoin price keeps increasing that makes it very hot transfers for traders. I never saw Bitcoin fee go back below 20sat/vB for a long time since the bull run started. Are you using trustwallet because I encountered same bullshit situation before using that wallet.
Bitcoin price increase has nothing really to do with the high transaction fee, it is just congestion by Ordinals that is causing it because of you check they are mostly the ones filling the block space with high transaction amount.
Also it is not TrustWallet that did that transaction because it doesn’t have an Opt in RBF bumping option and from the explorer the transaction is RBFed enabled.