I agree with @KurtSanders. Depends on your use-case.
I believe some here have well over 200 devices running with no issue. I prefer multiple hubs because I feel it not only reduces resource overheard on individual hubs but also helps reduce mesh issues.
https://community.hubitat.com/search?q=multiple%20hub
I have run multiple hubs by location - 2 C-4 hubs in 2 different areas of the house (main floor/upstairs) and that worked great. When the C-7 came out decided to migrate all my Z-Wave devices to it to take advantage of the newer 700 Series ZW Radio. Had a C-5 on hand so used that for Zigbee devices. My reasoning being the C-7 and C-5 Zigbee radios are the same/similar. For giggles also re-used one of the old C-4's to be my "cloud app / network devices" hub. So far other than some minor issues this setup is working very well. Have about 59 devices on the C-7, 77 on C-5 and about 10 devices (lutron + 1 hubmesh device) on the cloud hub.
The other thing I am doing to further reduce resource load is I have moved all my rules from RM to an external system running Node-RED. I feel it gives me greater control over my environment and allows me greater flexibility for connectivity etc.