Moving on from Agency to DIY as SME

Hey r/SEO I run a memorial card company based in Ireland, serving primarily Ireland and am at a crossroads with the SEO agency we have been using, and looking for some opinions. **TLDR:** I'm likely going to have to go DIY again and am wondering which whether I should opt for the Pro or Guru SEMrush price plans. Our area is niche but national and I'd likely only use it for this site. I have been using ubersuggest premium, but found its usefulness limited. I'm also unsure where to go to secure good enough backlinks if we stop using the agency. **More details:** I started working with the agency in March/April 2024, so for about 9/10 months, after the website had been live for about 18 months. I was initially doing the SEO myself, learning as I went and the metrics were looking promising, though the cap is relatively low due (maybe 2000 for highest volume keyword due to the area being local and niche), but then a series of issues (website hack, reverting to back up from several months prior and having to do most SEO work again) meant deciding to enlist an agency last year. The agency is on the lower/mid price tier (€1000 p/m), but were based in Ireland and generally seemed the most competent out of the few we were considering. I have been relatively pleased with them, and our metrics have been improving in terms of DA, impressions, clicks and conversions. We've done good work on the on page optimisation, improving pagespeedinsights metrics, and they are securing 12-18 backlinks of somewhat dubious quality per month (they were upfront about this being greyhat, but are confident it won't hurt us). We have less than 1000 at the moment. Our main competitors seem to be using blackhat backlinks (almost 10,000 for one of them) but aren't being penalised for it. However, its been 9 months, and I'm really struggling to justify continuing with them to my bosses as the conversions have not even covered their fee each month. While we have cracked the top three for a few keywords, they are low mostly volume, and the main high volume keywords we need are up and down like a yo-yo, and currently not even top ten especially for the primary, highest volume keyword “memorial cards” (average spot of 45 this as of this morning). I've had a couple of discussions with the agnecy about this, and we have tried alternative strategies securing fewer whitehat (“guest” p2p articles) backlinks since October, but with limited results, and I’m wondering if I should copy my competitors and go for blackhat in addition to grey/white. I'm aware these things take time, and have tried to convey it could take 6 to 12 months, but my bosses don't think its been worth it over all. Bottom line and everything. I'd appreciate your perspective. Thanks.