Which is Better? Laptop, Tablet, or 2-in-1

I think that would really depends on what one needs as well as what one can afford.
If someone needs to use/run more resource heavy programs like graphics/video editing, AI, machine learning... a tablet is probably not going to be enough. That would probably require a PC.
As to whether a laptop or 2-in1, that would most likely depend on money available.
A 2-in-1 with the same processor,RAM, and other hardware as a laptop seems to be usually more expansive than a laptop with the same specs.

I believe that a tablet is best for an educational experience because it has been proven that handwriting down notes helps students retain information. Typing doesn’t allow students to memorize information. 

Laptop.

I love my Yoga 2-in-1s! It's the best of both worlds. It has the easy portability convenience of a tablet, but with the power of running actual PC software instead of watered down mobile apps.

Laptop because it is portable, has enough storage and can run actual PC software.

This can be personal choice.  I find that I use a keyboard more than a touch screen.  But you can have that with any of the choices.   Lighter weight is nice, but battery life can suffer, and lighter sometimes means poor quality construction, and easier breakage.    I find a laptop the best for me, and can get by without a touch screen,  Like a real keyboard, a real mouse instead of a touchpad, or a touch screen, is much more comfortable for "mouse intensive" work.  

From my viewpoint it would probably be a laptop with or without the 2-in-1 feature. Whereas a tablet is very handy and quick it can be a little difficult to write notes on.

From my personal experience I think the 2n1 works better. It has all the same features as a laptop for work but you can still enjoy it in your personal life. Balance is the key I don't think I will ever go back to the traditional laptop

I think the 2-in-1 offers the most versatility. I've tried a tablet with a keyboard before and the experience is not great.

2-in-1 would be best as it allows the functionality of a laptop and tablet in different class settings as needed.