Bitcoin and Ethereum are still the best cryptocurrencies in the future because investors and traders have already accepted it. Because this is what new altcoins mimic. It is reliable and has been proven over the years. Even if the market falls, it can still surpass its previous all time highs. Many large investors and companies are already investing in bitcoin.
As we can see, the world is getting faster and faster. In my opinion, the future has those coins that accelerate the blockchain. Fast and cheap transactions, preferably free, this is our future.
And such projects already exist, even though they are far from perfect, the future will be built on them.
Free transactions may not be a good one. Looking at EOS today which its transactions are technically free, they're not growing. It could have been good but developers are not looking into it because the team has to have a lot of EOS to become a block producer to live up to their promise. Free transactions will not encourage demand for the token. I can agree that BTC and ETH are the only valuable these days.