This is far and away the most common cockroach I see. If you want to see a lot of them open up a sewer system. Oy vey. So with the sewer being a huge source, and you’ve got a lot running around, think plumbing problems. Check the toilets for rocking. If they move, the wax ring seal is ruined and the door is standing wide open to the sewer line. Pull the toilet. Repair the flange. Install a new wax ring. Reinstall the toilet and secure it so it doesn’t move. Door closed. There could be a broken vent or sewer line in the wall. Much more complicated than fixing a toilet. The other primary source is the outside. You’ll find them a lot in the landscape. Check your door sweeps. Make sure all outside doors have a good seal. If you have a garage, make sure the door leading into the garage is sealed. I’ve never seen a garage door that sealed effectively, so use pesticides and glue boards. Roaches have been around, unchanged, for a long time. I figure God created the cockroach, and said “Perfecto!” And with man it was version 1, version 2, etc.