Depending on the group you're adventuring in, a kick-arse familiar isn't really that good either. Someone will have one, or long-term summonables. If it's a dippy warlock boon, go extra cantrips. Even without the big book of ritual stuff, it's nicer than "get a weapon, or get a super familiar". It just is. Even without every ritual ever made, I'd rather the big-book-o'-cantrips. As a dippy thing, it's good. If you claim the ritual thing, it's better.
But not as good as +Charisma damage and push when you want it on Eldritch Blast. Hex, Scorching Ray, Fireball, do what you want. But a pushy cantrip with good damage is golden. You can pay for all the rituals you want later. Unless you need a scout, Chain isn't that good. Unless you have plenty of long-term summons (10min-1 hour). Then it's great with Voice of the Master. Until then, meh. After then, long-range-attack-force-of-doom. There's a lot of things you can command with your voice through a good familiar. Otherwise, it's pointless. Grab the free Guidance, Resistance and *whatever* from the Book. They don't stack, but it means you've got two party members with them if you already have a druid or cleric in the party. At worst, +d4 initiative to two people in your party, with a wisdom caster alongside you.