Blazer may start one day and then the next time wont

The problem is either fuel management or electrical. My first instinct is that even if it is fuel management it is still an electrical part.
Diagnsoing electrical part failure is really tough because the part slowly fails or fails intermitantly until it fails completley.
If you can, try to get a service station or dealer to put an OBD reader on your truck and see what codes come back.
My guess is it will be the fuel pmump/Main relay or the fuel pump itself.
But get a code first and get back to us.

If you poured fuel in the carb, that usually at least gets a sputter. If it does nothing from that. I would tend to agree with you. To be sure, the next time you try to start it pull a spark plug and see if it is wet with gas. If it is, then the problem is with the spark.
Test your coil with a multi-meter. Follow the link below by pasting it into the adress window of your browser. It is a good walk through of ignition sysstems and then there are links to diagnosis of each part. You can also search the site on your own and try to find a past question that applies to your specific model vehicle.

Here is the link;

https://www.2carpros.com/articles/how-an-ignition-system-works

I hope this helps.