The reason for more reactivity of more substituted alkyl halides for E2 Reaction is said to be due to the more stability of its more substituted alkene character having transition state but here (https://home.iitk.ac.in/~madhavr/CHM102/Lec13.pdf) at page 6 it is mentioned that:
The reaction rate increases with the increase in number of alkyl substituents on the carbon with the leaving group ($\alpha$-Carbon)
However, it further says that the reason is the relatively more stable transition state (which has partial double bond) due to the more alkyl substituents (probably Hyperconjugation effect). But my question is that Will not the stability of the same transition state increase if the $\beta$-carbon is also more substituted? Why it specifically mentions for the $\alpha$-carbon to be more substituted?