It is time Veigar received a rework
Unfortunately, veigar simply has no place in this game anymore in his current iteration. He was designed at a time when games had an average length of +40 minutes and you could become a late game monster. But now, games are far too fast for him to farm AP with his passive to offset his glaring weaknesses. His lane match ups, of which he had almost no good ones, have gotten even worse with the assassin buffs. Veigar always had a weak laning phase due to having no mobility and being really squishy with inefficient mana costs, but all of those problems are made worse by the new rune system. Speaking of new rune system, Veigar has no real good choices to make in regards to rune options. Some are better than others, but still pretty mediocre, at best.
I don't expect every champion to benefit to the same degree with the new runes, but it's clear that some champions need reworking if this is going to be the new system and veigar is at the top of that list.