what is the performance difference between get/setValues() and range.copyTo(destRange)?

Question

so I use apps script with sheets that have 100k+ rows so I want to know which methods have better performance, Normally, I use srcRange.getValues() and dstRange.setValues(dstData) to move data in sheets using apps script, however, I recently found that their performance drops significantly when trying to apply them on a range of about 20K cells, now I just want to know should I keep using them or think about using something like srcRange.copyTo(dstRange) instead if it's better performance wise.