What are the odds you write a binary search that you'll use more than once instead of just running it and writing down the result?
Every time I needed to write something algorithmically demanding, I could do it in a day or two. Im not into Leetcoding, or competitive coding.
Most regular everyday programmers can work these things out in one or two workdays.
Its definitely not like the competitive programmers say, like if you aren't into this full time, at the time you need to write something you won't have access to time, internet and even an IDE and have to write the code in a Google doc(which needs internet connection, when I pointed this out in the interviews they didn't like it).
When do you write code that doesn't need to search? (Unless you hand it all to the database, in which case... sure, you're good)