It highly depends on the industry but in health-tech, startups still opt for patent protection, simply because it works. For anything that is not suitable for patents, many founders opt for trade secret (as patents are open to everyone and can be used by competition to figure out how you're doing what you're doing).

Another strategy that I have seen experienced founder following is keeping their patent under examination for longer. They either respond late to the examiner's questions, purposefully opt for GAUs (Group art units. Different GAU reviews different tech patents) where the prosecution timeline is slower. This gives them extra time to keep their innovations hidden while still protected, until they are ready to enter market with viable products.

For AI based, software patents are a tricky game with many getting rejected under Alice 101 rejections. The drafting and prosecution methods also change a lot when dealing with software patents about AI.

I can share more in-detail if you have any specific question.

Context: I am not a founder but I work in a Patent and technology consultation company and we regularly help with prior art searching, patent monetization, and large scale patent analysis on industry.

I have talked to about 200 early stage founders last year through conferences or in-person interviews and talked specifically about this topic.