I did much more well with ETH (i am holder since 2015 too), so it compensates regarding the global multiples done.
No wonder you are confused.

I'm not confused. You just continue on the same way...
You don't like ETH (like many here) and it's not the problem, because we cannot compare BTC with ETH. But the fact is that ETH is not useless on many points. As it's still important to have cash/fiat right now too.
And I'm happy to have made so much money by investing on ETH. Nothing is full white or full black. You put maybe too much attribute on BTC and forget everything else.
But the life, the assets, investments is not ONLY BTC. And as a wise person, you probably perfectly know it's always better to dedicate your portfolio in many different ways (Bitcoin, some "shitcoins" as everything else is shit for you, stocks, real estate, different currencies etc.. in different banks and differents continents). As a optimized globalisation, to try to have a balance on the global risks.
Then you allow the % according your feeling and the risks you want to take ; it's another topic for the repartition.