Well, the Beneficial Ownership Information Report takes 15 min to fill in online and is not complicated - doesnt make sense to pay for that. And hasnt Trump removed it anyway?
For the annual state filing and state fees: Well, one sets up one's LLC in New Mexico where there is no state filing nor any recurring state fee.
For the annual 1120 and 5472 filing, that is a little bit complicated, and different accountants will tell you different things. I see it this way, that no third party will care as much as you about this, so best to be in control here oneself and not outsource it. It's not too difficult to find good information about this and even pay for advice - but best to file oneself.
And then you have the registered agent, cant escape this unless you have a friend living in the US willing to handle it. There are totally fine services that are worth paying for Id say.
And beside the initial setup (which is also worth paying for) that's it!