Traceroute can be a useful tool on your network, where you can compare the results to what is expected. On the public Internet, it can give you a completely different path than what actual data may take. Your traffic may pass through multiple ISPs, any or all of which can look for and redirect ICMP and traceroute in order to disguise their internal networks.

Your traceroute may be purposely routed over a backup or other path. It is also possible that there is some load balancing or instability happening with one ISP. You simply cannot know, and your actual web traffic may take a much better path than what you are seeing.