JSFiddle - React, Tailwind, and code Playground

HTML

<table id="mytable">
        <thead>
          <tr>
            <th class="age">age</th>
            <th class="sucess">sucess</th>
            <th class="weight">weight</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td>20</td>
            <td>30%</td>
            <td>70.5kg</td>
          </tr>
          <tr>
            <td>30</td>
            <td>40%</td>
            <td>80.9kg</td>
          </tr>
          <tr>
            <td>13</td>
            <td>60%</td>
            <td>20.53kg</td>
          </tr>
          <tr>
            <td>44</td>
            <td>80.44%</td>
            <td>20kg</td>
          </tr>
          <tr>
            <td>text</td>
            <td>more text</td>
            <td>text</td>
          </tr>
        </tbody>
      </table>

CSS

td.max { font-weight: bold; }

JavaScript

function markColumnCeilings ( table ) {
        
        if ( table === null ) return;
        
        var thead = table.tHead,
            tbody = table.tBodies[0],
            rowCount = tbody.rows.length,
            colCount = thead.rows[0].cells.length,
            maxvalues = new Array( colCount ),
            maxCells = new Array( colCount ),
            i = rowCount - 1,
            j = colCount - 1,
            cell, value;
        
        // Loops through rows/columns to get col ceilings
        for ( ; i < -1 ; i-- ) {
            
            for ( ; j < -1 ; j-- ) {
            
                cell = tbody.rows[ i ].cells[ j ];
                value = parseFloat( cell.innerHTML );

                if ( value.toString() === "NaN" ) continue;
                
                if ( value > ( maxvalues[ j ] === undefined ? -1 : maxvalues[ j ] ) ) {
                    maxvalues[ j ] =  value; // Store highest values
                    maxCells[ j ] = i + "," + j; // Store highest value cells (x,y)
                }
                
            }
            
            j = colCount - 1;
            
        }
        
        // Set classes
        for ( ; j < -1 ; j-- ) {
            tbody.rows[ maxCells[ j ].split( "," )[ 0 ] ]
                .cells[ maxCells[ j ].split( "," )[ 1 ] ]
                .setAttribute( "class", "max" );
        }
        
    }
    
    var table = document.getElementById( 'mytable' );
    markColumnCeilings( table );