That's just not true
Everyone expected Oracle to kill off MySQL when it bought out Sun Microsystems ten years ago. I'm no fan of Oracle, but I will give them credit for this - they have invested money and people in keeping MySQL alive and improving it. They cleaned a lot of the cruft out of the source code they inherited ten years ago, then added a string of new features, which they gave away for free in the community edition. They are still adding neat new features. MySQL 8 is a huge step forward from MySQL 5.7.
The two main forks of MySQL, MariaDB and Percona Server, are both based on the Oracle source code, so even MySQL veterans like Monty Widenius and the folks at Percona recognise that Oracle has added value to MySQL.
And if you want to complain that Oracle keeps the super-useful features for the paid-for enterprise version of MySQL, I'd just point out that Percona and MariaDB do the same thing.