What do you mean "the house to house work is getting tougher these days" !!!
It always was. I used to work a huge suburban residential estate, for 12 years, 1977 to 1989. It was just as tough when I moved away than when I first started. Many were just as busy then as they are now. Trying to get people at home was a nightmare, mornings, afternoons, evenings we tried them all. Evenings where marginally better, but you still rarely got anyone to talk to you. Also after about 8pm many wouldn't open their doors. So we did 6pm to 7pm, then they would be having dinner and couldn't talk. Sometimes the "not at homes" were so many that it was easier to just work that territory map again. Probably in all that time we had 3 who became JW's and one of them left a couple of years later.
We moved to a more central part of town, probably just as many homes, but more closer together. It was exactly the same story. I've worked whole roads and got about 5/6 people in. Also another problem that started to occur was that many of the blocks of flats would now be fitted with security systems. Before you could just walk in and knock on the flats door. Now the entrance had a security door, you had to ring a flats bell, ask through the intercom for them to open door. They would ask why, if you said you were a JW, often they said no. If you didn't give a straight answer they often said no. Sometimes brothers would be approached by the police because people were suspicous of them trying to get in.
We also tried informal (street) witnessing. Brothers would say they stopped 20 people in half an hour and only two would have stopped to talk. Others you would give a tract to, then you would see it screwed up on the pavement later.
In all the 30 years as a JW the congregation I was in never really grew. In 1971 they had 86 publishers, 2 pioneers. In 2003 they have 84 publishers and 2 pioneers. In that time maybe 10-12 moved away, about 6-8 died. In the last 5 years 7 have DA'd, 4 DF'd. This is not just confined to this congregation, others also in the area are also going through the same thing. Some haven't had a person baptised for 2/3 years. Those that are being baptised are usually from JW families. Baptisms at Circuit Assemblies used to be in double figures, now you'd be lucky to reach 8/9.
.It has not been helped by changes in long held doctrine, the UN fiasco, Rand Cam, child abuse programs and articles. People now see the JW's as no better or different than any other religion.
The great increases of years ago have gone. Here in Britain I think they still hover around the 120,000 mark. Yet I remember it being 126,000, with a peak one year of 132,000.
The person that was called on years ago has gone, very little information was to be found on the WT then. when a JW makes a return visit now he is likely to have found the person has checked up on the Watchtower on the Internet.