High load isn't necessarily an emergency, but it may be a heads-up before a site noticeably slows down. Sometimes there are weird spikes that just go away, but sometimes this is an indication of a Denial of Service.
If you have a current Drupal site (built in Drupal 8 or later) you no longer need to entirely rebuild your site -- ever again. That doesn't mean it couldn't use a freshening up now and then.
Over the past few months, I've fielded a lot of minor styling requests, and as I work through each problem, I've almost always ended up with substantially less code than was there before.
The world of the web has changed a ton over the past decade. Websites that show one page at a time with no animations or interactions can feel stale and outdated.
Here's an introduction to Progressive Enhancements:
Websites can do far more than just present information. Many business applications have moved onto the web, and with a CMS like Drupal in the back end, your website itself can be an integral part of your business.
After 15+ years, Google cut off our "forever free" business account yesterday.