Ethereum 2.0 finality time?

I'm trying to figure out the finality of Ethereum when it is fully upgraded in several years. After the merge, splurge, verge, surge, all that jazz, when Ethereum's roadmap is fully complete, what will it's finality time be?

With a 6.4 minute epoc time, will we need to wait 2.5 epocs as I've seen before? I'm wondering what Ethereum's final form will be and if we will still be waiting 15 minutes to consider a transaction final.

I'm extremely bullish on ETH, but if it's finality will never be under 15 minutes, there HAS to be other chains who will thrive with fast finality times. In my opinion if this is the case, it confirms that the future is multi-chain. Are there other solutions on Ethereum that I'm not aware of?

Thoughts?