What will happen if Tech Giants Like Google, Microsoft, Amazon starts investing in Bitcoin or Altcoin Mining?
tech giants like these that you named are too big to care about the profit they may get from bitcoin and remember that bitcoin is still not a fully established system but still in its beta initial phase and many even consider it risky and experimental.
those giants would either invest in something that can have a much bigger return 100 times bitcoin mining profit or if in a very unlikely scenario they decided to get in bitcoin they would buy and invest in it.
This is very true on which those big companies would really not bother to engage into bitcoin mining since they would see that they could only make small money with it infact they would rather choose to stick their traditional ways of making money which is even more bigger profits rather than on bitcoin mining. The would really not tend to jump on and you are right they would really hesitate since bitcoins value is still unstable and they dont like that for sure.