Earlier quoted context omitted.
This is blatant nonsense. The best security choice for any small business that doesn’t have a dedicated full time security staff is Microsoft 365.
Have you admined a Google Apps account and an MS365 account? I'm curious why you think Microsoft is more secure? For me they are completely different, Google is secure by default, Microsoft is not. Do you have "Direct Send" enabled on your account for example?
For a small business without a dedicated IT team, simply hire a IT contractor to harden the tenant (MFA etc…), have them review every six months and be done with it and focus your resources on running your business.