Our HOA is forced to use an email mailing list. Enough older people who don't use facebook... and now younger people who refuse. Maybe ask for a show of hands at the next meeting. Sentiments can change overnight. Especially with the meta stuff happening at the moment.
We use a SaaS provider for our HOA and it works well, but there is a monthly / annual cost for that. That said, people still insist on posting to Facebook but the group can easily turn to poison and sniping which is super awesome for being neighborly…