Until recently, Google Cloud didn't have reserved instances. Interestingly enough, last week they introduced their version of it called "Committed Use" pricing.
Here's what it looks like for 2 CPUs/8GB RAM (numbers below according to their documentation page):
AWS
On-demand = $69/month
1-year = $53/month
3-year = $47/month
GCP
On-demand = $52/month
1-year = $31/month
3-year = $22/month
In short. If your infrastructure is so small that it's about reserving 3 instances for a year. You should be running on Digital Ocean. It's much more simple and cheaper. You likely don't need the more advanced features from Google/Amazon.
If your infrastructure is in the hundred of VMs. Reserved instances are basically unusable, it's a NP complete problem to optimize capacity for a moving target. You're as likely to save 10% as to lose 20% on your reservations.
Last but not least. Reserved instances have many tricks and constraints that you'll only find out after you spend 10k on them, and can't go back.
TL;DR: Although AWS has a lot more cloud products, unless you need the additional options, IMHO the Google Cloud is more intuitive, cheaper and offers better cost structure (e.g. by-the-minute pricing instead of by-the-hour).
So if you’re starting a new project, I would highly recommend that you give the Google Cloud a try.