For example, in The Netherlands there is a legally mandated three-day period after signing the contract for purchasing a home during which the buyer can still call off the deal.

The reasoning for this is that it is a seller's market, with demand far outnumbering supply. In practice it is very common these days to end up in a bidding war, and even forego any kind of "sale is void if home inspection turns up issues" clause. Want to think about it for a day or two before signing the biggest contract of your life? Too bad, another buyer is willing to sign today.

With the mandatory three-day waiting period you avoid buyers being locked into a contract they basically immediately regret. It gives them some time to do due diligence, reducing the risk of buying a complete lemon. The seller can ask for a similar clause to be inserted, but it is less common. After all, the only risk to the seller is getting slightly less money for it, and that's already mostly dealt with during the bidding process.