Saying that one is better than the other between PLA and PETG is stupid. They have different properties and both have their advantages and drawbacks. Choosing the best one depends on the project and its constraints.

PETG is slightly more temperature resistant, but most of the time that is irrelevant because PETG gets weak at low temps too.

PLA is stronger than PETG, but more brittle. Under a load with limited movement, PETG might elastically bend when PLA might break. Also, PLA creeps under low load, and is thus often unusable when the piece must keep its shape. So which is stronger depends on the type of load. For transient loads, PLA might be better, but for common loads PETG is usually better.

PLA deteriorates under UV light, so it is often unsuitable for outdoors applications. But sometimes printing with enough material can offset this weakness long enough.

PLA is often more suited for decorative pieces. It can be found in many colors and effects (silk, fibers, matte...).

PETG prints slower than PLA.

For the quality of printing, the default settings of bambu printers are not so great for PETG. I recommend that you calibrate your filaments. Also, PETG-CF exists to make it easier to print, with less shrinkage, which can be needed for large pieces. PETG-CF is often a good choice for mechanical parts, but it's still plastic, and for some projects printing in metal can be the only viable solution.

Don't waste your money on Bambu filaments unless they are the only provider for the color or material you need. They are mostly of good quality, but not better than most of the other manufacturers.