It depends on the altcoins you want to buy. If you choose some solid project, I think you can make more than if you are just holding bitcoin. But make sure to spread your investment. I think ETH, Waves, NEO are some really safe bets, ELIX and PRL are also some nice opportunities imo.
But make sure to research your projects and only invest in those that you see useful long term.
Due to recent market dips you can get lesser known, lower cap coins with potential for 50-70% off their ATH prices so those (especially the ones that had the bad luck to be released in the market after January with all that was going on) are prime candidates to pick up and have better returns in comparison to the heavy hitter coins when the market cap is bullish but in a reserved way.