I think it's important to have boundaries. If you continually excel and exceed expectations in your role, then eventually there will be a "big ask" that's far beyond your abilities, and they know it, and they won't care, because on paper you're just that good.
I think it's also difficult to hold any boundaries, if everyone around you is grinding, and working 16-hour days 6 days a week, and living at the office or working from home. But, it depends on company culture too. I've learned to get a feel for how much work-life balance will be at any given employer. And eventually you just settle into that one role that's a good fit, and doesn't ask too much, and you establish a smooth flow that's sustainable.
My current job is self-limiting, as it is part-time, and so I am not allowed to clock more than 29 hours per week. So even as a WFH gig, it's not possible for me to be workaholic; eventually at the end of the week, I need to disconnect and take a breather, and do something like a hobby or recreation. Also, my department is really laid-back, and we're not paid based on doing things quickly, so we're encouraged to be diligent and do a good job, not a rush job.
My job description is one line. One sentence, one line job description. I'm not required to go outside that description, even informally; I'm paid to do what's on the page, and I'm not paid to do anything else. Since the boundaries are crystal clear in this way, and management is so very supportive, even when I'm stressed and faltering, I have a really sustainable flow, and I won't burn out.