You can't parse CSV this way, because you need to respect delimiters. Counter example:
1,"1,5",2
"1,5" being the German notation for "1.5". Hence, a simple split(',') will break this thing.
PHP's str_getcsv is, of course, a proper CSV parser and not a string splitter. Unless your code uses basically zero stdlib API calls, you will have to double check everything.
Please note that this kind of bug isn't even easy to catch if you test CSV file doesn't contain a quoted entry.
This is very cool. Interestingly GPT appears to be incorrect when it suggests in the differences, that str_getcsv would not parse correctly quoted parts. It does look like the php function has support for the "enclosure" character hence something like "1,5" should parse correctly.
PHP's str_getcsv is, of course, a proper CSV parser and not a string splitter. Unless your code uses basically zero stdlib API calls, you will have to double check everything.
Please note that this kind of bug isn't even easy to catch if you test CSV file doesn't contain a quoted entry.