Is a slow maybe worse for a customer than an outright no ?

I used to be terrible at giving direct answers because I hated disappointing people or turning down feature requests. So I'd just say "let me look into it" and leave users hanging for weeks while I tried to figure it out. Looking back that silence was way more frustrating for them than a simple "we aren't building this right now" would have ever been. People can handle a rejection they just hate being ignored or strung along.

How do you usually handle feature requests you know you'll never actually work on?