Firewalls, absolute nessecity or a nuisance?

I’ve been thinking about this in regard to another topic regarding cloud storage. Suppose you host your own cloud. Would it be wise to have a firewall?
If so, what would that have to be? Hardware or software? (Like ufw?)
I’m new to the world of firewalls, hence my question.

most people dont use firewalls, and rely on destination nat for their security.

Firewalls are still usefull. it can be a device other than your host that can block of connections and do complex routing. such as l2l VPS and BGP routing. I personally would like to have them to help line private networks across my clouds in vpn tunnels

Host your own cloud as in make your home network accessible from outside? At that point, personally, I would absolutely have a dedicated piece of hardware to handle your firewall (implying, yes, have one).

I’m not hosting anything and I have plans in the works to setup a dedicated box I’ll probably run PFsense on. That doesn’t mean I will get rid of any ufw/iptables rules I have set locally on any of my machines, just means I’ll have that full network level protection. Help me feel more comfortable about machines I have less control over (like the partner’s).

With the right homework and patience, a firewall can’t be a bad idea. Especially if you’re going to be exposing things in any manner, in my opinion.