Yes, they do need more options, BUT, as an interesting side note, they are excellent as villains. Really. Try using one.
"Evil wizards" are traditional villains and imho Sorcerers are very, very good in the role, better than frail Wizards. Draconic ancenstry. Chaotic magic. More importantly, some very useful features, especially from draconic blood...
- Augmented HP and AC, which is great for guys whose role is being beaten by swords and magic;
- Some metamagic tricks (notably Quickened and Twinned spells) are great to wreak havok with your limited high level spells. I Twinned a Chain Lightining to great effects once and I still smile thinking of that metamagic moment;
- Being probably higher level than the PCs, limited nr. of spells and limited sorcery points will not be an issue, not going to last long anyway;
- Finally, at high level they can fly and resist some damage which is not bad.
So, great Evil Wizard Villains Sorcerers do, I say.