In some cases using match heights can cause your page to run slow. We recommend using CSS where possible.

If you use match heights on a lot of elements on the page and you have a lot of other javascript running, it can cause your page to run slow. 

We recommend using match heights only when you cannot achieve horizontal alignment with CSS alone. In many cases using flex CSS properties, you can achieve match heights. Using CSS alone rather than javascript will improve the performance of your website.