These, eToro and the like, aren't "brokers" so much as online betting platforms for the stock market.
A typical broker like Interactive Brokers, Charles Schwab etc. acts as a gateway to the market, other traders act as counterparties, and is bound by strict regulation
These "neo brokers" as you call them don't. Those "securities" you're buying are offered by the broker, at a price set by the broker, the broker may be the counterparty and they can't be transferred. Just like a casino.
This is all laid out in the terms and conditions for anybody who cares to read them, e.g. [0], sections 7.1 and 17.
If you want to gamble based on stock prices using leverage, at least do it right: use derivatives. They're leveraged but thoroughly regulated and traded on central exchanges.
[0]: https://www.etoro.com/wp-content/uploads/2025/10/eToro-EU-Te...