Chinese language: why 店 and 电 are pronounced in the same way?

店电 : Pinyin - diàn
There are dozens of Chinese words that have the totally same pronunciation (include tone) as 店 or 电.
All the following commonly used words are pronounced in the same as 电 or 店.
Here just list a few of them.
Traditional: 墊殿甸奠澱佃惦.
Simplified: 垫殿甸奠淀佃惦.
And, there are more than I just listed.
Normally, in spoken language, it’s needed to say more than one word to make anyone understand what we are talking about.