There is nothing new about what you are doing as I've seen it as early as 2017 during that ICO craze when each and every Telegram group was filled with similar spam and is as effective as ANN thread bumping that we can still see here. Either case, a total waste of money.
Good potential projects are using better ways for marketing and promoting. Spamming with many messages all over the telegram or Twitter we only bother the community managers and moderator to ban those bot continuously
Tbh, all altcoin projects spam and shill to some degree, some just have more money so they can buy Twitter and YT influencers while low level go for OP's "marketing" technique.