What's the out of pocket limit on each plan?

Does the employer provide any deductible funding for the HDHP?

It's certainly possible your employer structured their contribution policy poorly, but generally there's something that would explain why there's such a small spread on those plans.

Generally speaking the markets do not feature negative returns year after year. Historical evidence gives us relative confidence that eventually the money in the market will outperform a HYSA.

And because you are unlikely to be able to accurately time the market reliably, investing into the down period is at least getting your money into the market at a relative discount.