Main reason being it's just easier and narrows down the choice of picking an inverter, which causes a lot of people to get stuck trying to find the right one that fits their "scenario" perfectly.

But also hybrid does everything you need and the cost savings of something else is marginal from what I've seen. It's an "all in one" that I believe is a good one size fits all for 99% of the houses out there. Every house should have a 5/10kw inverter installed by default with a corresponding set of solar and battery pack. I.e.

5kw solar panels, 5kw inverter, 5kwh battery bank. Or 10 or 15. It acts as a giant ups, let's you shift some power, and you can gradually reduce your grid reliance to almoat 0 by adding more batteries, all while staying on the grid just in case.