The Bitcoin network is the first blockchain and still the most widely supported. Every crypto casino that accepts crypto at all accepts BTC. Security is this network's strongest property: the chain is protected by the largest computing power in the world.
In a casino context: three limitations
Speed. A new block arrives on average every 10 minutes. Casinos usually require 1–3 confirmations, so a deposit arrives in 10–30 minutes. Compared with seconds on Tron or Solana, that is an eternity.
The fee fluctuates. The network fee depends on how many transactions are waiting in the mempool. On a quiet day it is small; on a busy day, several euros. For a small withdrawal the fee can eat a substantial share of the amount.
Exchange-rate risk. BTC is not a stablecoin. The rate moves between deposit and withdrawal, and that movement can be larger than your win. See exchange-rate risk.
When BTC is still the right choice
For larger sums, where the fee stays small as a percentage and universal support matters more than speed. And when both sides support Lightning — that solves both speed and fee, turning a transfer into seconds and cents.