Short answer: yes, for a lot of brands, and often better than a team. Longer answer: it depends on your size and your budget, and I will tell you where the line is, including where it stops being me.
Why do siloed teams leak results?
The usual setup is an ads person, an SEO person, and a web person who rarely talk. Each is good at their part. The problem lives in the gaps between them. The landing page the web person built does not match the promise the ad makes. The tracking breaks somewhere between the campaign and the site, so nobody is optimizing on real conversions. The paid work and the SEO work chase different keywords because the two never compared notes. None of these are skill problems. They are coordination problems, and coordination is the first thing to fall apart across three separate people.
When does one full-stack person win?
When your campaigns, your tracking, and your landing pages are built by the same person, they fit together by default. There are no handoffs to lose things in, because there are no handoffs. For most small to mid-sized brands, that beats having a dedicated specialist per channel. You move faster, the funnel behaves as one system, and one person owns the whole result instead of each owning a slice and pointing at the next.
When does it not win?
If you are spending very large budgets that justify a deep specialist per channel, or you need all three worked on heavily at the same time, one person becomes the bottleneck. I would rather say that up front than take work I cannot do justice to. Knowing the edge of your own capacity is part of the job.
Why I can do all three
I did not read about these jobs. I did them. Over the last decade, each of paid media, SEO, and web development was my actual day job at some point, which is why I can build the page, wire the tracking, run the campaign, and write the copy without waiting on anyone. When it all comes from one person, nothing falls between the teams, because there are no teams. Just me.
If that sounds like the fit your brand needs, book a call and tell me what you are trying to move.