I wouldn’t bother with Xfinity Business unless i was running a public facing server. You don’t need it.

Ive been an Xfinity Customer for 16 yrs. Only option I have is consolidated communications( hideous dsl with speeds of about 7mbs).
I have never owned my own modem. Xfinity does updates to the modem to keep it current Dos 3.1 machine. If a modem shits the bed you can bring it back and they will give you a new one. Go and price out a new highly rated 3.1 dos modem and they are not cheap. I dont have to worry about upgrading and downloading to the modem patches and fixes. Yes I pay rental of $15/mo.
Get a gig from xfinity for less than $100/mo for a 3 yr contract, or pay 3x that with Comcast Business. These days response times for a problem is much faster than 5 yrs ago. Both Xfinity and Comcast Business offer month to month or longer contracts.
I am sure there are cheaper companies, but I can have as many devices on my wifi and never have any devices lag.
My money is on the most speed I can get, reliability, and they provide the service I need.
Both my wife ( many are overseas) and I are home based workers and are on Teams call, emails, contracts, etc.
My 2 cents.
Good luck !