This weekend, I was having similar wonderings to the OP. I've been using products from Adam's Polishes for many years now; it seems to be a company run by a bunch of car enthusiasts, which helps me trust that their products will work the way the product label indicates. I also love their library of YouTube videos on exterior and interior detailing how-to's and tips'n'tricks.
I was watching through the video about engine bay detailing:
Their recommendation is to take a pressure washer to the engine compartment.
With all the sensors and electronics I can see in our engine bays, a pressure washer seems like the easy button for a Christmas tree array of CELs next time I start the car. This can't be how folks really clean their engine compartments? So I'd love to know how folks here approach a good engine compartment cleaning — or if y'all just leave it to the professionals.