Personally, I would definitely choose Bitcoin, let alone investing with EOS, if the comparison is Ethereum, I would definitely choose Bitcoin. As far as I know, Bitcoin is the first cryptocurrency created, which has given rise to many other cryptocurrencies until now, and they are called altcoins.
Ethereum is ranked 2nd on Coingecko and I would definitely choose Bitcoin if there was a comparison between the two. Maybe EOS used to be ranked 2nd on Coingecko, but the proof is that now EOS is Dump and is not included in the top 30 on Coingecko. This is only my definition and everyone has full choice in his hand. Good Luck.