I've been ripped off so many times for thousands of dollars in total over the years that I only now pay in the arrears.
I make an informal contract of what is expected, and if those goals are not met, I will prorate it to what should be paid out and terminate the deal or keep them on if they catch up and meet the expectations going forward. I understand that life happens and some people may not make it, and have empathy for that, so I do still pay out the full amount in cases like that with a promise of catching up if they are motivated to keep going, as it's not that much from the prorated amount to the total.
I should put it in a more formal agreement, but I have so much on my plate.
Anyone who's worked with me, and that's a lot, can attest that I pay out almost immediately upon request of their end of the deal. I don't have an "employee management system" in place yet to go over each person and make the payments beforehand, so I do rely on them to notify me for now. I hope to also get to this portion soon enough as I grow because I will have more than 20 on the payroll and it'll be easier to go down a list all at once as opposed to opening email by email and then going to make an individual payment when it can all be done in one swoop or click of the button.
This is how the normal workforce works. You don't show up to McDonald's on day 1 and get paid for your week. You are paid at the end of the week when your hours are logged. Therefore, I don't think this is a big ask. However, I do realize freelancing is different. Though, I make it very clear that it's paid in the arrears and if they don't want it like that, they can walk, cause I'm not going to lose even a dollar more.
I make some exceptions, but very few. These are for trusted people or using a 3rd party service like Fiverr where it can be disputed more easily than a PayPal dispute that takes days, weeks, sometimes even months, to only be denied with so much mounting evidence.