Yes lack of time affects relationships especially if its a long distance relationship. Am a victim and i wouldn't advise anyone to deal with long distance relationships if you know very well your cannot afford to communicate. Especially if you're both working, you'll find yourself being busy and by the end of the day, you feel so tired and just retire to bed. One partner on the other hand will feel like you're assuming them or might even think that you have moved on with someone else.
Lack of time doesn't only affect long distance relationships but even when you're staying at the same place. The man comes home late night when the woman is asleep and wakes up very early. They only spend less time together in the name of job. This behavior continues and becomes an trend. With time the woman starts feeling suspicious about her husband/boyfriend. They end up arguing and this might lead to breaking up.
As long you both of you know each other well, there's no need of being suspicious. Whenever both of you have free time, its good to spend it well to avoid querrels.