If you're a materialist and you think there is no afterlife then I don't believe there would be a void. There's no mechanism for "you" to perceive a void or perceive time.

Its the difference between:

"I see nothing when I close my eyes" (actually you 'see' darkness over time)

and...

"I see nothing through my elbow" (You really don't see anything through your elbow because the capacity for it just doesn't exist.)

Even our basic perception of time is mediated by the structure of our brains... and without that there's no difference between one second and a trillion^trillion years.

Being a materialist and claiming that everything is the consequence of physical phenomena is great, but then you have a lot of homework to do. So I see no more strength in its claims than in the contrarian ones.