Baccarat is a good place to test betting systems because the banker bet carries a small edge, a little over one percent. Take a C$2 base unit and a table that caps bets at C$200, and walk four popular systems to the point where they stop working.
Martingale: double after every loss
The ladder runs C$2, C$4, C$8, C$16, C$32, C$64, C$128. The next rung would be C$256, which the table refuses. Seven straight losses on banker happen roughly once in every hundred and forty sequences, and when they do the player is down C$254 with no way to continue. Every successful sequence earned C$2. The system trades a long string of small wins for one occasional loss that erases them all.
Fibonacci: add the last two bets
The sequence goes C$2, C$2, C$4, C$6, C$10, C$16, C$26, C$42, C$68, C$110, C$178, eleven steps before the cap intervenes. The climb is gentler. The catch is on the way down: a win moves you back only two steps, so recovering from a deep run requires several wins in a row, during which the bets stay large.
D'Alembert: one unit up after a loss, one unit down after a win
This one rarely hits the table maximum. What it does instead is leave you betting eight or ten units for a long stretch after a bad run, because each win only trims a single unit. The expected loss is still the edge multiplied by total money wagered, and the total wagered under D'Alembert during a losing stretch is considerable.
Labouchère: cross off the ends of a list
Write down 1, 2, 3, 4. Bet the sum of the first and last numbers, five units; cross both off after a win, add the lost amount to the end after a loss. In practice the list grows after a few losses until the required bet collides with the cap or the bankroll, and the whole sequence is abandoned at its most expensive point.
Where they all break
The same place: the sum of the expected values of the individual bets. Rearranging bet sizes changes how losses are distributed across time, never their total in expectation. A long-form explainer on Casino Bossy simulated all four over ten thousand hands and the final columns were almost identical. Systems can be pleasant structure for an evening, and they are played by adults of legal gambling age who understand that structure is all they provide.