Others have said, but I will underline:
New accounts start at ~2350 (Initial Competitive Skill Rating, Decrypted). Five placement games is not enough to rank an account accurately. Quick play is not taken into account. Accounts with 150+ recent games are accurate, so your bronze account is much closer to your “true” rating.
Old accounts are not hard stuck, unless the player who plays them is hard stuck. If the account is given to a stronger player, it will climb. At worst case (established low bronze account, GM player), it takes several hundred games to move the account to the new player’s rating. Note that the majority of these games are at higher SR, when it becomes more difficult to climb. Here’s some data: Stevo's Bronze to GM Analyzed - Google Sheets. Stevo won his first 51 games (from bronze till plat). The data is old, but the basic mechanics of climbing hasn’t changed that much.
A gold player would have no trouble getting a bronze account out of bronze, but closer to high silver/low gold he’ll slow down.
That you asked for a boost to prove you wrong, and then came up with a lamesauce reason why to reject someone who agreed, makes this whole thread and video look rather lamesauce. You’re not looking for answers, you just want just find some excuse for your low rating other than your low ability.
Finally, see How Competitive Matchmaking and Rating Works (Season 18) for more information about how things work.