Almost anything will scare off some readers in some contexts. That does not make them wrong things. It just makes the things that appeal to one person more than another. No work of art or communication should strive to appeal to anyone other than its natural audience.
If someone is looking for videos, text will scare them off.
If people are looking for short easy answers, long answers will scare them off (even if a long answer is needed).
The point is, there is a place for large blocks of text. If you are using a large block of text when a large block of text is appropriate, it is fine. It won't scare off someone who is looking for a substantial written answer.
It is generally a good idea to break text into fairly short paragraphs, particularly on line. This seems to make text easier to read. The definition of a paragraph is fuzzy at best: "a distinct section of a piece of writing, usually dealing with a single theme and indicated by a new line, indentation, or numbering." How big is a theme? Themes are fractal, bigger theme are made up of smaller themes. Paragraphs are therefore quite and arbitrary unit, and they have been getting steadily shorter over the last couple of centuries.
What you do need to be aware of, though, is information scent. Readers on the web have a wealth of sources available to them and this encourages them to make quick decisions about a page and move on quickly if it does not meet their needs. This means that you need to establish what is called "information scent". Stack Exchange is full of information scent clues.
Questions create information scent. Upvotes create information scent. If a user is looking for a piece of code they can copy, code blocks create information scent.
A block of text gets its information scent from its context and from its opening sentence. If the information scent continues to grow as the reader moves on, they will keep reading. If the information scent flags or is never established, they will stop.
A block of text may not have as strong an initial information scent as a video, a diagram, or a code block. This does not make text blocks scary, it just means it needs to do a good job of being focused and on target. If a block of text is the right vehicle for saying what needs to be said, then use a block of text.
If you are an advertiser, you might decide to use a picture or a video to try to grab the attention of an unmotivated reader. Unmotivated readers are not likely to be drawn to large blocks of text. This is probably where the idea of the "text wall" came from. But it turns out that long form content actually works better for content marketing purposes than pictures of kittens. Why? Because it attracts motivated readers.
A motivated reader is not scared by a block of text if there is a reasonable indication that that block of text contains the information they are looking for. There are different rules for essayist and novelists than there are for carnival barkers. We should not be dragged down to the lowest common denominator of communication.