If Hardy proved that there are infinite zeros lying on the critical line, does not that mean he proved the Riemann Hypothesis? This is an exerpt of the wiki page covering Riemann Hypothesis: *" Thus, if the hypothesis is correct, **all the non-trivial zeros** lie on the critical line consisting of the complex numbers \+ i t, where t is a real number and i is the imaginary unit. " * When they say "all", it means that all the non-trivial must lie on the critical line, and Hardy proved that there are infinite zeros of that type ( i.e $Re(s) =\frac{1}{2}$).

No: remember that there are infinitely many even integers, but there are also infinitely many odd integers. Equally, there are infinitely many primes, but "most" integers are not prime.

Hardy's proof shows there are infinitely many on the critical line, but says nothing about what proportion are. By proportion, we mean $$\lim_{T \to \infty} \frac{\text{number of zeros with real part $1/2$ and imaginary part between $0$ and $T$}}{\text{number of zeros in critical strip with imaginary part between $0$ and $T$}}.$$ (the even number-integer analogue has proportion half, for example: half of integers are even. On the other hand, there are about $n/\log{n}$ primes less than $n$, so the proportion of positive integers that are prime is zero.) The best estimate on the proportion that lie on the critical line was provided by Conrey (1989).