Competitor with junk backlinks, how should I compete?

Hi all, I'm not an expert in SEO by any means but I just want to hear people's advice on how to figure this situation out. I have no backlinks for my new site as of now, so I'm looking through one of my main relevant competitors backlink profile on semrush. I've come across some pretty junk-ish websites that link to them and I can't tell if it's helping or hurting them, seems like helping. They are ranking high, usually #1, and steadily growing, no harsh drops offs/spikes from the keyword/traffic graphs. They have 50K Backlinks, 48K being Follow. 1K Referring domains. 90% of them come from a single website which I'm going to assume they own too. The rest are all from a really wide array of random websites in various different languages/niches. Which leads me to believe they are just buying stuff off Fiverr or somewhere else. Any filters or metrics I should narrow down on semrush to help me develop a plan to start competing with them? Thanks for the help.