If a survey or whatever funds something you do not like, that should happen before you pay a deposit. If you waited, that was your choice.
If you are buying a property yourself, you will have a deposit from the seller. If you are selling but have not found a property to buy yet, you should not proceed to the phase you bind yourself to sell yet. That means that your buyers might find other options while you find something for yourself of course.
Which is exactly what happens anyway right now, with the difference that people will pull off at the last minute.
There is nothing wrong with deposits, they just move decision time earlier on.
Life can happen even earlier on. But sometimes, maybe often, people will not pull off even if life happened, because who knows, maybe things will change, or because they are engaging in wishful thinking.
And let's be honest, most times life happens right at the time of sales because of the system. It allows people not to commit until the luggage is at the door, so people will leave a lot of decisions to the last minute.
Give them an obligation to pay 5 to 10% months ahead, instead, and if they are not sure, if the want more cash, if they want to pay less, they will address that concern earlier.
It is a demented system right now. A bunch of people window shopping and stretching really thin, due to an overinflated market.