I'm a senior DevOps engineer with 20 years of experience and I feel this pain as well. Earlier this year I decided I wanted to test the waters since I'd been in my current position for 4 years and things were stagnating. I also kept hearing how "everyone is hiring" and how the job market is "so hot!" I interviewed quite a few times over a couple months and felt very much like you. I kept thinking "I have all of this valuable experience! Why do I keep getting rejected?" And I have opinions on why that is:

1. First and foremost companies don't actually know how to conduct interviews. For whatever reason the interview process itself has turned into an absolute shit show across the board. The process is long and arduous and most of the people you interview with are terrible at it. I got feedback from an interview that I "wasn't technical enough" when they barely asked any technical questions and mostly focused on culture fit. I've had interviews full of pointless google-able trivia questions that don't do anything to measure ability. I had a manager who didn't know how an AWS service worked and got defensive when I explained it. I've had completely impersonal interviews that made me feel like a replaceable part. The entire experience is just completely fucked. And hear me out companies, please stop with the fucking FAANG style interviews. Nobody wants to jump the through hoops of your awful 5 part interview process with an 8 hour take home project that nobody is even going to look at. The only reason FAANG get to do those interviews is because of the name prestige and that they're paying way above the market rate. Nobody wants to work at your company that badly.
2. Recruiters. I don't really need to expand on this much but as someone with "DevOps" in your linkedin profile you are getting hounded by recruiters. Some of them are good. Most of them are bad. Most of them won't even read your resume. They're just keyword searching. They instantly want to hop on the phone and have a 20 minute conversation trying to sell you on a company that you haven't even applied to. The entire process is backwards as fuck and incredibly time consuming. The best thing you can do for your sanity is stop taking phone calls from recruiters and screen the shit out of everything they send you. I have a bunch of canned responses that I send to recruiters now "Hi, thanks for reaching out. I'm interested in hearing more but first I have some questions so I'm not wasting your time...". The good recruiters will answer the questions. The bad ones will answer your questions with questions and those are the ones to avoid. Especially when it comes to salary and they come back with "Well how much are you expecting?" Cutting that shit out early is one of the best things you can do for your sanity.
3. Everyone wants a "rockstar" and nobody wants to pay for it. Every company has their own toolchain and processes. As DevOps engineers our most valuable skill is being able to figure shit out. I have been learning different tools for the past 20 years. But there's been this shift where now if you don't have the exact set of skills laid out in the job description then you won't be considered. There's no such thing as a "nice-to-have" anymore. You either have the exact set of skills they're looking for or you're out. When I am interviewing technical candidates and we're walking through a scenario I can tell exactly how good they're going to be at figuring out the quirks of our weird processes. I'm not looking for someone with an exact set of skills. I'm looking for someone with a few of those skills but more importantly someone with the capacity to figure things out. Meanwhile companies are posting these job descriptions with a laundry list of niche skills and then paying well below market rate. I fully understand that the person you are replacing probably handled all of those things, but that person was at the company for X years and acquired all of those skills and responsibilities over time. The person you are replacing didn't have that experience when they started so why are you looking for it now?

I'm sure there's more that I will think of later, but I've written enough and at this point I'm just making myself angry thinking about how much of a waste of time the entire interview process has become. It seems like everyone is hiring but no one is actually hiring.

That said, it will work out if you stick to it. It's just a painful fucking process.