Often their members aren't really interested in the on-line version of church, so that takes a back seat to other things.
I have a problem with this. It is 2023 and the web is over 30 years old (I know because it existed when I got married and I just celebrated my 30th anniversary). Even if you're not streaming services or doing social media like FB, having a website that is welcoming, up-to-date, and accurately reflects your congregation is a must just for marketing purposes, IMHO. A church that is neglecting the online world to the point of not even looking after their web presence is pretty clearly one that is living in the past and probably not that interested in anyone under the age of 60 or even 70 who might come in with newfangled ideas like, "Hey, let's start a Facebook group." And I don't want to be in that church. Simply the act of neglecting the online world reflects badly on an organization, in other words, and makes me think twice about them.
The Unitarian fellowship here in London is small and struggling but still managed to revamp their website this year into one of the best church sites in London. They clearly recognize the importance and value of online presence in the 21st century. I was a part of that, taking their original half-assed website and whipping it into shape something like 20 years ago. It has had two redesigns since I gave it up, both prompted by a recognition that you can't stay still online.
Frankly, if a church doesn't have a decent online presence, I likely won't even notice them and for most people younger than me, even that probably won't be enough. They rely more on social media than even the web. You need to be on Tik Tok or Instagram to get the attention of Gen Z, for instance. Just look at jazz singer Laufey, a 24-year-old who has largely built her career on clever use of Tik Tok and other social media and in doing so, actually got Gen Z interested in jazz.
If you don't have the expertise inhouse, hire someone. There's plenty of hired gun designers out there and they are not that expensive. And keeping a site updated with current information is a breeze in the era of content management systems like Wordpress. Hell, I could build a good, easily managed, church site using Xenforo and some add-ons and styling.
/rant off