Sorry for the long post, but...
I'll give you the different point of view of someone that has, dare I say, more than just a M1 Mac...
I have a Surface Book 2, which has great battery life, is totally silent during normal use, has decent power and a great keyboard (these are the features for the M1 Macs, sure they are more powerful, but I guess most people are more than fine with a quad core i7, and sure hard core mac users don't want windows, but again the vast majority of people are fine or even prefer Windows), plus it has touch and pen support, it has a pen magnetically attached to the side of the screen, has a 3.2 screen and can turn into a large but still light tablet.
So many of the things that people have said, being intimate, being able to scroll with your fingers, using pen etc, are all there. And still I have several iPad pros and minis. And a Galaxy S7+. Why?
I have never tried to replace my laptop. iPadOS (and Android) is far from being able to do that.
What I have replaced with my iPads is paper (I used to print a lot, I have replace books, I have replaced sheet music) an pen (mainly for annotating and I often do for work). I have replaced my TV (I know some people like having a huge TV, I don't, I want to watch stuff while being mobile around the house). And the TV apps often works better on tablet than on a browser.
And I use them for youtube and movies (as TV, youtube and movies my S7+ is probably the most used device).
I use them (mainly the 12.9) as a second screen for work, because in my work I need to have either pdf files or power point files always open in addition to the rest. So most of the time I don't connect them as a monitor, just open the files and keep them as a second wireless touchscreen I can take everywhere together with my laptop. So I replaced a portable monitor. And I have portable USB C monitor. but there is no such thing as a 4.3 portable monitor, which is essential for my work.
I don't videoedit much, but when I do, I find lumafusion much nicer than a desktop videoeditor.
iPads allow me to pick the right size. From the mini to the 11 to the 12.9 depending on what I need it for (mini in bed for instance, 11 for reading books when not in bed).
They have replaced my newspaper. I subscribe to a financial newspaper which I use with its iPad app (again, 12.9 on my desk, 11 when I am standing, mini in bed)
Do I browse on them? Only when I am not at my desk, otherwise I browse from my Surface book (and I love the ability to have touch on it).
I use iPad with cellular when I am on the go and I might night to type something (I don't have the magic keyboard, too heavy for me, defeats the purpose, I use the apple smart keyboard, or some logitech ones, and the brydge for the mini). So iPad has replace a laptop on the go, unless I know I need to work on the go.
Could I do some of these things on my Surface book? Yes, but it's so good as a laptop that that's what I mostly use it for (and that's the device I use most during the day), but sometimes I do detach the screen to continue watching a video that I started watching on my desk and that's a nice option. And iPads give me more options in terms of size and some things are better on apps (like my newspaper does not have a windows apps and the browser version is much inferior)
I could go on with more niche uses but the post is already long enough...
If my surface book was running M1 would it replaced my tablets? Maybe the 12.9... Otherwise, not really, having iPad apps would help, but I still would not have the small sizes. And 4.3 is better than 3.2 for most books etc. And, let's be honest, Macs with touch, pen, detachable screens and square aspect ratios are not happening.
And a M1 mac as they are now would be a big downgrade for me as a laptop, since I don't need more power and I would lose all the nice things that my surface book offers (and I am not in the Apple ecosystem anyway since I have a Samsung phone...)