1. We have to place bets with a coefficient of about x2.
2. We must have some kind of strategy that allows most of these bets to have an advantage over the bookmaker's line.
3. This advantage in a stable form is likely to manifest itself over a very long distance (about 1000 bets)
Of course, no one forces you to make 1,000 bets per year. Perhaps you will do so much in just a few years. It's just about not losing your money, despite the fact that you have a good strategy overall, but you don't take into account the possibility of adverse variance.
If you do not have a reliable strategy that would allow you to have an advantage over the bookmaker's line with a coefficient of 2, then, of course, small bets will not bring you much benefit. But in any case, they won't let you lose your bankroll too quickly.
I think that in reality everything works a little differently (although of course there are always exceptions), I will assume that the average player makes about two bets per week (as I understand it, we are discussing bets), this will be approximately 10 bets per month, in a year this will be about 100 bets, I think this is the average for the majority of players.
As for the bankroll, the same average player is unlikely to deposit more than $100, and in this case no one will divide 1/1000 with such a budget, at best it will be 1/100 (that is, 1%) and in practice, players can bet 10% or even more if they are confident in the bet, therefore the risks are higher, the adrenaline is stronger and the loss has a greater impact on the bank. Players risk more than 1% per bet because in the end it becomes boring to play for $1, you will not be able to win anything significant and you will hardly worry about such a bet, which means you will not get the emotions that you will get if you bet 10% or more.
We can`t talk about common gambler - i don`t think that the gamblers with 2 bets per week will plan his bankroll for a year at least. Such player will bet as much if he decide that moment.
But i can agree that 1/1000 bankroll is too small bet. It may be correct bet, but you need huge bankroll to feel the interest to such bets.