I liked working with Microchip uC, but this was back when the whole IC (PIC24) was described in a single ~1000 page document. I found it very readable and instructive in general.
If I had to pick something today it would be with RP2040/2350. The docs look awesome and there's a huge community that is not locked down in some corporate moderated forum but spread organically, with actually useful GitHub projects. It is the only embedded product where it felt like the open source community is along for the ride and not just picking up the scraps. I hope they continue this line of products.
The PIC24 was actually my first large project. I learned awful lot from reading its docs, for example setting the DMA to read 32 samples from ADC and let CPU know when done. Putting it together felt like playing with LEGO blocks. There were many annoyances with the toolchain and the clumsy memory addressing but I enjoyed it overall.
The NXP was downright unpleasant compared to it. I don't think a junior could be handed a NXP dev board and all the docs to hone their craft. It requires significant patience and expertise to pick out the relevant details in the vastness of their documentation. Of course the NXP product line is huge and I can only comment on few uC models I had contact with. The sensors and other less complex ICs were vastly better and docs were quite digestable.