The answering machine is, on the one hand, very convenient for both a person who calls and a person who is called, but, on the other hand, unnatural because you can't talk directly with the other person.
(e).
ストレスは、一方では害になることもあるが、他方では生活のいい刺激にもなるそうだ。
It is said that stress is sometimes harmful for humans, but, on the other hand, it also seems to be a good stimulus for human life.
Life in a foreign country is, on the one hand, enjoyable because one can encounter new culture, but, on the other hand, it is sometimes hard because of culture shock.
Formation
Nounは
一方ではS1 Conjunction,他方ではS2
この薬は、一方では症状を軽くするが、他方では強い副作用がある
This medicine, on (the) one hand, alleviates symptoms but on the other hand, it has strong side effects