If they ask you this question, it's because they already want to deny you entry.
But with the crackdown currently going on, it's likely going to get asked to more people than previously.
Who has and has not been asked literally makes no difference for you. If you are asked, you must have it or you will be denied entry. It's as simple as that. Even if 1 million people before you were not asked, you must legally have proof of funds to enter Thailand as a tourist.
That's a question for your immigration office. Some will require it to be in a single transfer, and some will allow multiple transfers to meet the requirement. You need to ask your immigration office.
SunnyPhoenix2325 You apply when the money has been in your bank account long enough. You apply at an immigration office. It's called an extension, not a new visa from an embassy outside of Thailand.