On AWS, multi region involves setting up VPN and NAT instances. Not rocket science, but wasted brain cycles.
Generally, with GCP setting up clusters that span three regions should provide ample high availability and most users don't need to deal with the multi cloud headaches. KISS. You can even get pretty good latency between regions if you setup North Carolina, South Carolina, and Iowa. Soon West Coast clusters will be possible between Oregon and Los Angels (region coming soon).