Why isn't there a huge difference for reading time numerical Excel files between readtable, xlsread and readmatrix?

Hi All

I did a benchmarking between readtable, xlsread, and readmatrix, knowing that xlsread is somehow deprecated. I had a really small difference between xlsread and readtable that I will lose again when converting table elements to arrays. The file is an 14336 x 7 (rows x columns) xlsx file. is there a way to speed it up considerably ?

>> xls=xlsread(fname);
>> rdt= readtable(fname);
>> tic;xls=xlsread(fname);toc;
Elapsed time is 2.230238 seconds.
>> tic;rdt= readtable(fname);toc;
Elapsed time is 2.156550 seconds.
>> tic;rdt= readmatrix(fname);toc;
Elapsed time is 2.511168 seconds.