[javscript][Algorism] Filter Function Question

Hello, the code below is

Both the people and tshirts arrays are arranged in ascending order

const fp = people.filter(person => {
        For(let item of tshirts){ // Change the array value if you are looking for person in tshirt array
            if(person <= item){
                tshirts.splice(tshirts.indexOf(item),1)
                return person <= item;
            }
        }
    });
    return fp.length;

In fact, what I'm looking for is elements in the peson sequence that are less than or equal to elements in the tshirts sequence. While I was thinking about how to find it, I thought, 1. Let's make an array that fits the condition and return the length of the array, and I wrote the above code because I thought it would be best to use the filter method to make an array that fits the condition.

However, the filter function is usually most useful when returning is omitted as shown below and only an array that meets the conditions is extracted immediately.

const result = words.filter(word => word.length > 6);

In the code I made,

And so... I'm asking you a question because I think there's a better way to do it.

I understand that you have to write functions such as redox, map, and filter well to extract an array that meets the conditions. Is it best to use the filter function in this case? I'd like to ask you how to write a cleaner and more beautiful code.

Thank you for reading my question! :)