You're right that a design, verification and test bench can easily rack-up several hundred thousand dollars worth of equipment.

But there are trade-offs that can lower the capital cost, like leasing the equipment, using a third party for aspects of the design/test, carefully evolving known good designs and simply budgeting a lot more for more PCB re-spins.

In the finally analysis those to want to make products in this domain aren't doing it on a shoestring budget, it's going to cost a lot no matter what.