"You should properly research your keywords and build them into your content to create a holistic whole. Google is looking for relevance to searches not keywords."
I see this sentence used repeatedly in the advice given and wonder how it works in my particular circumstance. Using a frequently used search phrase of "Electric Fencing"
https://www.screwfix.com is shown at the top of the organic search despite having no content bar a few products. Title and description are no better and no heading tags.
That's what you said in your original post.
Here's some thoughts.
1: "You should properly research your keywords and build them into your content" - you clearly understand the importance of this but I can see obvious content problems on your home page which I know will not be helping you to rank higher for the two word phrase "electric fencing" and I can see other problems on a number of internal pages that I know are not helping you to rank better for "electric fencing for horses" and also "electric fences for chickens".
2: Why, when I do a keyword search in Google Chrome for "electric fencing for chickens" do I see two different urls (within your own website) ranking one behind the other, on page 2 for that same keyword search?
3: Why, when I do a keyword search in Safari for "electric fencing for chickens" do I see your home page and two other (of your) internal urls also ranking on page 2 one behind the other for that same keyword search?
4: Why on earth is your home page ranking for "electric fencing for horses"? Your home page should be targeting "electric fencing" and if you want to rank for "electric fencing for horses" then create specific copy on an internal page for it.
On the surface it looks to me like you've done the keyword research but you haven't done much work at all to allow 'sufficient keyword separation' from one piece of page copy to the next one and when Google sees things like this happening, it can't decide which page is the best one to rank for that keyword search, it rotates a variety of pages to see which one gets the most clicks. Whilst it's doing this, it moves your rankings down until it finds what it thinks is the
most relevant page within your site to show for a given keyword. Traditionally, Google doesn't often get clarity on things like this (unless the site owner sees the problem happening and fixes it) so this situation just keeps going around in circles.
Solution: Get some properly constructured copy on your home page which better focuses on the topic of 'electric fencing' (currently, your copy isn't) and include an FAQ section (on the home page) with copy which clearly answers questions often raised by potential buyers. Do not bundle a mix of other keywords into the same page
unless they are fully supportive of your primary keyword target.
Horses, chickens, snails and elephants... these words have no role in aiding your home page to rank for electric fencing.
Hope that helps.
Ray