As a cleric, you select your deity and then worship them, not that that means anything in DnD anymore. As a Warlock, you don’t pick your patron, usually, you either stumble upon them, they find you, or maybe you do get to pick. I see Warlocks as much more random, especially what you might receive. Apologies if I misunderstood which of your examples was bespoke.In my view, the difference between the cleric-deity relationship and the warlock-patron relationship is kind of like the difference between off-the-rack and bespoke.
I think making EB a class feature is fine, but I’m still not happy with the damage cantrip spam for days element of spellcasting overall. I wish there was more there that would make them more interesting, and I don’t mean by just adding riders. It’s just too easy.