All DPS clears highlight a problem with encounter design in ShB

[Rilifane]

Are a lot of teams clearing this raid tier with only one healer already? Is it already the standard?
Genuinely asking, just did Fulmination Savage (Ramuh) here.

No.
A few parties give it a go but because of some annoying "targets both healers" mechanics, it's too much of a hassle for most parties because it requires additional coordination. And the last mechanics of most boss fights aren't nearly as annoying as Cycles or Black Smokers, so skipping them is nice but not that much of a gain.
Not even ex trials get solo healed on a regular basis although the healring requirement there is laughably low.

The healign requirement would allow solo healing but it's just not worth the risk for most parties.

Replacing tanks and healers the moment you can is standard practice in MMOs. FFXIV is just more restrictive because of how some mechanics target and 2/2/4 is the standard comp. In other MMOs you can freely chose the number of healer you take with you. In prog you generally start with one additional healer and later replace them.
You don't have a standard comp, you adjust the amount of tanks and healers to your need.