It is absolutely the fault of PHP. You absolutely can compare IEEE floats using equality. Often it isn't what you want but this totally should work.

In this case PHP is unexpectedly rounding floats for display.

    ~ python3
    Python 3.9.13 (main, May 24 2022, 21:28:44)
    [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
    Type "help", "copyright", "credits" or "license" for more information.
    >>> b = 46333.48000000001
    >>> b
    46333.48000000001
    ~ php -a
    Interactive shell

    php > $b = 46333.48000000001;
    php > echo $b;
    46333.48