How did sambal and sriracha become ubiquitous with Middle Eastern food like falafel and schwarma?

I do not associate sambal with Middle Eastern food, but rather Indonesia food. The food of today has blurred the line between cultures with fantastic results. If you study the fusion, you will see how many cultures have similar ingredients, but different. Even my explanation is blurred.

I have had falafel in Israel served with hot sauce, but something indigenous. (Ever had zhug, a hot sauce with Yemenite origins, very popular in Israel? I doubt it was that, but that would be more 'from the culture' than Asian condiments.)

Sure. Those answers all make sense. I should've clarified more, I meant a quick service type places that are more focused on schwarmas and sandwiches. My bet would've been on the availability and put sriracha on everything mentality, just wondering if there was more of a history to it than that. Thanks.

I've never seen sambal or sriracha served with felafel or schwarma. But if I had to guess, I'd say it's either

1) because they're easier to find, and perhaps more versatile, than harissa, or

2) a victim of the "let's put sriracha on everything!" trend (see also: bacon)

I'm not sure that "ubiquitous" is exactly true but sambal and sriracha have a lot in common with the popular Tunisian table condiment harrissa. I would agree that they complement the same types of foods.