The framing of "is it worth it" assumes there's a clear right answer, but it really depends on what you're comparing it to and what your actual goals are. 3.5% APY on Coinbase is definitely lower than the 8 - 12% rates you could get in 2024, but you're not really choosing between staking and nothing. You're choosing between staking at 3.5%, holding unstaked (which gives you 0% but keeps your coins liquid), or putting the money somewhere else entirely. If you genuinely believe ETH will appreciate over time anyway, adding even 3.5% on top of that isn't bad, especially if you're not planning to sell soon.
The bigger question is whether you actually need that liquidity. If you stake on Coinbase, you can unstake and have your coins back in a few days - it's not like old-school staking where your coins were locked for months. So there's no real lockup penalty anymore on most major platforms. You're essentially choosing between a guaranteed 3.5% return and the possibility of needing quick access to your coins. If you think you might need to move them or want flexibility, staying unstaked makes sense. But if this is money you're comfortable holding for years, 3.5% compounds and adds up over time.
One thing to watch: Coinbase takes a cut of those rewards (around 15% or so, though check their current terms). So you're not getting the full 3.5% - it's a bit less. That said, if rates stay where they are, staking still beats leaving money in a savings account, and it certainly beats holding cash. It's not a home run like it was in 2024, but it's passive income on assets you're already holding. I'd stake it if you don't think you'll need the coins in the next year or two.