What uses does my warlock familiar have besides aiding and scouting? [duplicate]

So my DM last session ruled that my imp cannot help me perform checks (in this instance I was trying to have my little guy help me pick through some dead guards pockets) because he deemed that giving me advantage on most checks all the time is OP. Also my imp has to make stealth checks every time he enters a room to scout regardless if he is invisible or not, which hasn’t always ended too well. So my question is, outside of those two roles, what use is my imp? It seems to me that all the creative ideas that I’ve read about using a familiar are bound to what the DM would rule. Should I see if my DM will let me change my pact? Or should I try to convince him to ease up on my familiar? Thanks!