Have you checked how kms (kernel mode setting) has been configured ?
I had a ThinkPad T550 with - as I recall - the same configuration and it worked quite well using Intel.
Manjaro took a break from Plymouth back in 2017. I don’t recall when it returned - a couple of years perhaps, time moves fast in my age - but is started with Gnome (I think) and has slowly returned.
The configuration is important - it is not enough to remove quiet and splash - one needs also removing plymouth from mkinitcpio.conf
See these topics on configuring and removing respectively