phpMyAdmin is a great tool. It has been the default way to get at a MySQL database from a browser for twenty years, it is on virtually every shared host, and for a developer who already knows the schema it is genuinely useful. I have personally used it many times with many different databases. However, none of that makes it the right thing to hand a client who needs to correct a customer's address.
It is terrifying for a non-technical user
The first thing a client sees is a list of every table in the database, named the way the developers named them. Nothing distinguishes the table they need from the session store, the migrations table or the audit log. The information they came for is in there somewhere, and finding it is their problem.
Nothing it does is reversible
There is no undo. A mistyped WHERE clause, a Delete clicked on the wrong row, a paste into the wrong column — each of those is committed the moment it is confirmed, and the only route back is a restore from backup or manually fixing it (provided the user can remember what the original values were.
Worse still, if it's given to someone who thinks they know SQL and are able to enter whatever query they like...
Clients know this, which is why the more careful ones stop touching the database at all and start emailing you instead to do their minor edits.
It asks questions only a developer can answer
Foreign keys are shown as the integers they are, so a client editing an order sees customer_id 4821 rather than a customer's name. Enum columns offer their raw values. Dates want a particular format. Every one of those is a question the interface cannot answer for them.
The cost lands on you
Either the client does not use it, and the routine data changes you hoped to hand over come back to you as support requests; or they do use it, and you find out when something breaks. Neither outcome is what giving them access was meant to achieve.
What to give them instead
The requirement is narrower than a database administration tool: read and edit the tables that matter, with labels a human recognizes, relationships resolved to names, and permissions that make the dangerous things impossible rather than merely discouraged.
That is what Redbrix does — it connects to the MySQL or MariaDB database you already have and gives your clients an interface built for them rather than for you. There is a live demo if you would rather look than read, and a side-by-side comparison of the two.