Wix vs Wordpress
There is a lot of bullshit going on about wix and wordpress right now.
In short: Wix is the overwhelming leader for "do it youself" websites today. Easier to use, faster, less expensive. The solution was created in +/-2008. It was not reliable until +/-2013, but after that, they took the world (and the Nasdaq!) by storm. The system is amazing, but has 1 main limitation: you cannot set-up a database for the moment.
So… If you need a website which doesn’t require a database: use Wix. If you need a website with a database, for example to allow your clients/members to login. Use wordpress or combine wix with a wordpress module as we did with www.atel.lu for example for their Members directory.
For agencies, selling a wordpress website is more interesting. It is more complicated, takes more time, requires professional maintenance and therefore generates bigger budgets. So on this topic, agencies can hardly be a ‘neutral’ adviser. I hope that helps.