That's true, I guess I should have expressed that slightly differently - my point was that the only capability you can't get from "just" a smart switch irrespec

That's true, I guess I should have expressed that slightly differently - my point was that the only capability you can't get from "just" a smart switch irrespective of your choice of bulbs is changing colour. But also, smart bulbs with a dumb dimmer is the worst combination, so if upgrading somewhere, if it has dimmer switches that's an extra reason to replace the switch too, irrespective of whether you also replace the bulbs...