I have used the BSC, TRX and TON network really well and the one I can see to be very fast is the BSC network especially when sending out USDT stable coin through the network. I have used others I mentioned also in several occasions but my top pick is the BSC network. Congestions may happen time to time in the network but I haven’t been stuck in a network congestion that is not allowing my transaction to pass through quickly. According to Coigecko statistics, Solana seems to take the first position but since I’ve not used that network as much as I can remember, I can’t say confidently that it is very fast like the rest that I’ve used.
As far as I thought that Ton network is the fastest network because among the ones I have done transactions on so far, TON network transactions seemed to me to be the fastest. Is this just my opinion or is it true that at that time I got the fastest transactions on any network congested issue reasons, I can't say.
However, I think that transaction speed is a big matter for altcoins. If we talk about bitcoin, it is already successful in terms of security and trust, but altcoins are its alternative. In this case, since security and trust are already present in bitcoin, improving other aspects such as transaction speed to gain market share for altcoins will definitely be a plus point for them.