I am in a humanities field that sounds like it might be close to or the same as yours, and I have sat on multiple hiring panels for lecturerships, both permanent fulltime posts (these are advertised only rarely so we have been fortunate in our department to even get approval to create permanent posts) and fixed-term full-time posts. Fixed-term posts are more common, and there are hundreds of applicants, but they are hellish things in which the poor postholder must do a shitload of teaching while simultaneously publishing frantically and building as much capital as they can in order to get a permanent job at the end of the fixed term one.
Even for fixed-term jobs, which aren't as desirable (and there is zero guarantee of a job at the end of it), the standard amongst applicants is insanely high. No one gets through the longlisting unless they have their PhD in hand. Many have at least one book, and if not a book then several articles, at least one of which will be in a very good, recognizable journal. You also will not get one of these fixed-term posts without already having plenty of teaching experience, as we need to be sure that whoever the postholder is, they can simply hit the ground running and teach/mark/lecture on whatever we need them to teach, which might end up being quite some way from their area of expertise. And we've always been able to hire people who hit all these marks, and who are terrific colleagues, and have learnt that horrible lesson that early-career academics have to learn or they won't survive, which is: as dysfunctional and unfair as everything around you is, and despite the many officially and unofficially-sanctioned inequities you will see daily, you must STFU. Never say anything critical about the people around you, listen very carefully when other people gossip but do not contribute, and for the love of god do not go on about how things were done at your last university. (Well, actually, we've one chap who does this last one, in department meetings no less, and he is not paying attention to the eye-rolling around him when he does, so we'll see how that works out for him.)
I say all this not just to give you some insight into what the standard is even for fixed-term lectureships, but also to make clear what doesn't appear to be at all obvious from the outside: that working in a humanities department at this point in time is brutal. If you want to live the life of the mind, you have to scrape time for that from the huge burden of teaching (and, for permanent staff, also administrative) labor that will be loaded onto you. One good thing is that these days, there is plenty of talk about how miserable this is on social media, unlike pre-2000s when it was harder to find out what things were really like 'on the inside'. (That stuff used to be on Twitter, and since it turned into X it's not as easy to find, but no doubt it has migrated to bits of Instagram and TikTok so you will find it there.) I see my brilliant junior colleagues who have burnt themselves out during their fixed-term jobs increasingly making the decision to leave academia for more humane jobs and careers, and I salute them. Do a PhD if you like, and if you can find the funding (climbing aboard someone else's project as a funded PhD student is a good option though the competition for those is fierce as well: are you sensing a theme here?!), but please do not be under any illusions that teaching at a university, whether on a fixed term, permanent or (the worst option of all) poorly-paid zero-hours contract, will be anything other than exhausting and soul-destroying. The hour in the classroom talking to bright-eyed students about interesting things will be fun, yes. But you have to ask yourself whether everything that comes along with it - including the terrible pay, if it's hourly-paid - is worth it.
(I have experience teaching across the sector, by the way - RG, Oxbridge, others - as well as friends and colleagues with their own battle tales to tell from different institutions. Every one of those places has its own dysfunctions. And Oxbridge might be the most inequitable of all when it comes to hourly-paid teaching and fixed-term posts.)