Why do I get so many lag spikes?

Concerning dsl internet and MY PARTNER AND I constantly find lag spikes.I’ve known as my isp a whole bunch of times, and in addition they say the issue may be on my personal end caused by poor quality belonging to the phone outlines.So We were wondering if that could be true or not, just in case so will switching for you to cable internet solve this problem

Your ISP is most likely BT knowning that would describe why your own service sucks.