The answer to the last two questions is easy - yes to both.
There are absolutely huge differences between budget consumer and high-end professional equipment. There are also huge differences between high-end audiophile and professional equipment - the former being designed to flatter and enhance the sound, the latter being as neutral as possible.
A good few years ago a high-end audiophile CD/DAC maker was caught deliberately rolling off the top end on their equipment to make it sound smoother and "less digital."
It wasn't accurate, but a lot of people liked the sound enough to pay five figures for the boxes they made.
Professional audio has a different goal. The aim is to create a mix that "translates" - sounds good on as many different systems as possible, from budget earbuds to audiophile.
For a long time studios used a pair of shitty Yamaha bookshelf speakers called NS10s next to their ultra-expensive reference speakers. NS10s were almost the worst speaker ever. But if a mix sounded good on the NS10s, it sounded good on anything.