Having used them myself in the past translation sites like google translate, can be very useful for people who don’t have a lot of knowledge of English but there are times the translating sites are not the best option.
Those times are when you want to write an essay or trying to read something and instead of trying to translate a single word you attempt to translate a whole text or a sentence. Translating sites and apps are not made for whole sentences but for single words that you might not know what they mean. I see a lot of people especially in my German class that try to write essays and they end up writing nonsense just because they didn’t know how to, and they used a translating site. You have a better chance of searching on google how to say something rather than using a translating site.
The best ways and times to use a translating site is when you don’t know how to say a word or what it means and to find better sounding and more professional synonyms to replace simple words with in order to impress your teacher or boss. Other than that I really think you should find a better solution rather than try to translate everything from sites.