Lets take the universe. Stars, planets, moons, suns etc. Give it a age. Roughly 14 billion years old , according to science. Now, give the modern human an age. Around 25 000 years old. Put this into your 14 billion year old timeline. It doesn't even register, right?
Cellphones. 30 years give or take. Add this to the timeline. Again, its so insignificant, it doesn't carry any weight.
Ok. Think of the evolution of technology within the last 30 years. From the first cellphone, to the newest on the market, we came a long way. Imagine cellphones in 50 years, 100 years, 1000 years or even 100 000 years from now...
Take this 50, 100, 1000 and 100 000 years, and also add them to the timeline. Yet again, they dont compete against a 14 billion year old timeline.
So, if an planet was 100 or 10 000 years older then ours, (which is nothing in a 14 billion year timeline, and very plausible) they would have the technology now, that we will get to in that time, which makes us still stone age dwelling sims.
There are frequencies around us, we cant hear. Colors are not limited to those which we identified, we are limited only to which colors we see.
Dont be a dick to aliens.