He is sort of right, back in 2019. Even then, IBM PowerPC mainframe are still thriving.
Now, new language with cross compilation with some maturity are here. Major cloud providers now have ARM base machines ready, even designing to their own need.
ARM is in the datacenter market and become a trend.
The only thing I worried about, is the architecture of ARM are too fractured. AWS Graviton might behave differently than Ampere Altra, despite both have the ARM ISA.